Overview

If AMD's HD 7970 debut Southern Islands card arrived in a fancy tux heralding a bunch of world firsts (first PCIe 3.0 card, first DirectX 11.1-compatible), this HD 7750 turns up to little fanfare in a Burton polo shirt and trainers.

The new Graphics Core Next's architecture has already been shown off by the HD 7970 and those 4.3 billion transistors pack quite a punch, as it turns out, trouncing the very best of last generations' GPUs by around 20-30% at mega-high res.

The HD 7970 is also excruciatingly pricey though. At £440 its staggering performance and overclocking capability are out of reach to most gamers.

The HD 7750 should arrive hitting the right side of £80, making it an altogether friendlier proposal, and these new-gen AMD cards boast some excellent power efficiency by shutting off all but one core when your system enters power save mode.

But what's this HD 7750 missing out on to hit that price point? Does it still make high-res screens sing?

Benchmarks

We put the HD 7750 through its paces in the super-taxing Heaven 2.5 benchmark at a gigantic 2560 x 1600 and stressed every nanometre of its circuitry in the most demanding DX11 games at 1920 x 1080.

The HD 7750 bested Nvidia's rival sub-£100 card, the GTX 550 Ti, but came a cropper against the HD 6770.

DirectX 11 tessellation performance: Heaven 2.5: Frames per second: Higher is better

AMD HD 7750: 9.4
AMD HD 6770: 8.0
EVGA GTX 550 Ti: 8.9

DirectX 11 gaming performance: Frames per second: Higher is better

DiRT 3

AMD HD 7750: 28.64
AMD HD 6770: 36.83
AMD HD 6850: 42.62

Shogun 2

AMD HD 7750: 20.33
AMD HD 6770: 25.85
AMD HD 6850: 32.0

Metro 2033

AMD HD 7750: 11.67
AMD HD 6770: 10.33
AMD HD 6850: 15.67

Just Cause 2

AMD HD 7750: 26.13
AMD HD 6770: 26.19
AMD HD 6850: 34.14

Verdict

Our opinions on this freshman 'Cape Verde' chip are dependent on UK pricing. If the $95 US price converts somewhere near the actual exchange rate without too much mark-up, it'll be available at £80 or less, and if that's the case you'll be getting some great performance returns for your outlay if you skipped a generation or two in your graphics card upgrade schedule.

If that UK price falls closer to the £100 mark though, it'll be a misfire, rather than one of those classic AMD bargains you wait for with each new gen's advent. The HD 7750 is quicker than its big Nvidia rival, the GTX 550 Ti, and its predecessor, the HD 5770 - but not the HD 6770.

General performance is limited primarily by a slender 128-bit frame buffer, however the die-shrink down from 45nm to 28nm and increase in transistor count that comes with it gives this Southern Islands card a definite edge in tessellation-heavy tasks. It's apparent in its strong Heaven 2.5 score, but in non-synthetic benchmarks the performance gain from the new architecture isn't as noticeable.

Overclocking the HD 7750's a mixed bag, too. On the one hand, it handles big core and memory clock increases smoothly and without crashes - we had ours cranked up to 900 MHz on the core clock from the 800 MHz stock setting without any glitching or hangs.

The downside though, is that we didn't really achieve a whole lot of performance increase by doing so – it only reported a 0.1 FPS increase when we ran the Heaven 2.5 benchmark. That, along with general performance, is likely to change as the 7700 series' drivers mature though.

We liked

We'll get a better idea of the HD 7750's true worth when firm UK prices arrive, AMD's drivers optimise and third parties get their overclocking mitts on it, but at present all evidence points to a strong budget card that'll appeal to anyone playing at 1080p or lower, and keeps an eye on power efficiency.

We disliked

We're hoping there's more potential under the bonnet for overclocking performance than we were able to extract with the early drivers, since AMD's flagship 7-series card the HD 7970 overclocked so damn well.

If it doesn't work out that way, this card still offers enough stock performance over its peers to make it worth a look.

Overview

AMD showed its hand first in this year's GPU arms race with Nvidia... by turning it into last year's arms race.

While Nvidia has kept shtum about its upcoming new 'Kepler' architecture and looks to do so until Spring, AMD stole the march and released the first of its new 7-series cards, the AMD HD 7970, a few days before Christmas 2011.

That sure was odd timing, but it taught us a lot about AMD's new Southern Islands architecture, specifically the 'Tahiti' chip. It's fully PCIe 3.0-supported, uses a 28nm manufacturing process to pack more transistors onto a PCB than ever before, and apart from offering very quick DX11 game frame rates, it's a highly energy efficient beast.

When your system drifts off into standby, the Tahiti card switches itself all but off too, minimising power draw.

The HD 7970's whopping £440 price made all those neat features all but irrelevant to the gaming masses though, so we're putting our hopes on this HD 7770 to deliver the best bits of the new AMD architecture for a more palatable price.

The 'Cape Verde' chip that this HD 7770 is built around makes full use of the new Graphics Core Next architecture like its big bro, with ZeroCore power efficiency in tow and a solid 1,000 MHz core clock. If it can offer a slice of the HD 7970's performance for this price, it's on to a winner.

Architecture, technology and specifications

The Graphics Core Next architecture is a bold move from AMD in that it represents a move away from the VLIW instruction used in 6-series cards towards a GPU-processing-friendly SIMD vector processor.

The previous processor type was great for graphics processing, but not suited to general purpose GPU computing - AMD left that side of things up to Nvidia and its CUDA cores.

Graphics Core Next is a u-turn on that philosophy though. GCN allows up to 16 data elements to be processed in a single clock cycle.

Grouping data before it runs through the vector processor is really efficient when dealing with general processing tasks - but the bad news for games is that you won't notice that difference in Battlefield 3 - the strengths of this architecture are wider-reaching than that, even as far as the professional market.

GCN also understands advanced languages like C++, meaning that in the long run, it'll be easier for developers to make use of the 7-series cards for complex programs.

The performance improvement from this architecture comes from passing data through a ton of compute units, which all work on the same operation until it's completed, and the resulting compute performance of this HD 7770 card is impressive at 1.28 TFLOPS.

It's built with ten compute units rather than the HD 7970's sixteen, but that's still enough to demonstrate a marked performance increase on last generation's equivalent model. And with AMD and Nvidia now adopting similar stances in their design, it's becoming an increasingly straight battle between the two - no hiding behind the blurred lines of CUDA cores and stream processors.

So the number of compute units and the simplified SIMD instructions they perform give AMD's 7-series cards the brains, but the clock speed is still the brawn of the operation. And at a world-first 1,000 MHz, it's fair to say the HD 7770 has brawn in check.

Benchmarks

We tested the HD 7770 with the most demanding DX11 around at 1080p, and with the Heaven 2.5 benchmark at 2560 x 1600 to really test its limits. It fared reasonably, demonstrating why it's more expensive than the HD 7750 and keeping in the same ball park as the pricier but older HD 6850.

DirectX 11 tessellation performance: Frames per second: Higher is betterHeaven 2.5

AMD HD 7770: 11.9
AMD HD 6850: 12.5
EVGA GTX 550 Ti: 8.9

DirectX 11 gaming performance: Frames per second: Higher is better

DiRT 3

AMD HD 7770: 41.73
AMD HD 7750: 28.64
AMD HD 6850: 42.62

Shogun 2

AMD HD 7770: 30.77
AMD HD 7750: 20.33
AMD HD 6850: 31.86

Metro 2033

AMD HD 7770: 13.00
AMD HD 7750: 11.67
AMD HD 6850: 15.67

Just Cause 2

AMD HD 7770: 31.18
AMD HD 7750: 26.13
AMD HD 6850: 34.14

Verdict

Many of the HD 7770's new features won't be noticeable right away. The underlying architecture is a big step forward for AMD that programmers and developers will find attractive, but for gamers looking to get playable frame rates out of DX11 games at 1080p its benefits aren't as obvious.

We're expecting the HD 7770 to enter at around the £100 point, which means it's going up against Nvidia's 550 Ti. While we didn't see it outperform the Nvidia card by the 100% AMD implied, it does hold a clear performance advantage, in addition to the subtler features under its bonnet.

Our sticking point though is that it was outclassed in every benchmark we ran by the previous generations' darling; the HD 6850. With just £20 difference between the two cards, we'd have liked to have seen a closer battle between the two.

It's worth mentioning that AMD's drivers tend to get better results from any given card after a few months of refinement, so further down the line we might see more parity in the benchmark figures between the two cards.

As with the HD 7750, the HD 7770 didn't impress in its overclocking performance the way AMD's high-end HD 7970 did. That £440 card maxed out AMD's overclocking software settings before crashing; the same can't be said here.

We managed to add on another 50 MHz to the core and memory clocks which yielded a modest increase in our benchmark tests, but it wasn't a reliable runner with those settings - glitches and crashes kicked in after a few minutes. Hopefully we'll see the full extent of the HD 7770's potential when the third party manufacturers release their beefed-up versions.

The 7-series might not all deliver staggering performance and overclocking, and that's to be expected given their wildly different pricings, but there is one feature that consistently impresses across the range - ZeroCore.

This is power-efficiency taken to a happy extreme – when your system enters a long-idle state, the HD 7700 along with all 7-series cards completely powers down the fan, 3D engine, compute units, shaders – virtually the whole card. The only activity going on comes from a small bus control block, which simply lets your computer know that the card still exists and no-one stole the GPU while it's been asleep.

We found it to be fast-acting, and dramatically reduced power draw when our system went idle.

We liked

This HD 7770 brings AMD's new architectural features to the budget audience with reasonable success.

Its GCN design and ZeroCore power efficiency make it a compelling argument to choose new over old, but it doesn't quite blow the best of the 6-series cards out of the water in plain old gaming performance.

We disliked

The HD 6850 can't do the 7-series cards' tricks, but it can render Metro 2033 frames quicker, and that makes the HD 7770 a tricky one to recommend.

As a stock card, it doesn't offer anything outstanding, but aftermarket companies might yet yield some impressive performances out of it.

Overview

Sapphire has waded in first with its take on AMD's latest HD 7000 series card, the Sapphire Radeon HD 7950 OverClock edition.

Unlike the AMD Radeon HD 7970 there are unlikely to be very many strictly reference models of the Radeon HD 7950. Instead we're more likely to see card manufacturers taking the opportunity to put their own spin on the PCB, clocks and cooling.

The HD 7970 was a reference model all the way down the line, with overclocked versions only coming much further down the release schedule. The Radeon HD 7950 though is being freed by AMD to allow manufacturers to do whatever they like right from day one.

With the impressive performance of the reference AMD Radeon HD 7950, which we've already seen, any improvement on that is going to be very welcome indeed.

And anything that offers even more overclocking potential with this already blazing fast GPU is just dandy in our books.

AMD's biggest card manufacturer, Sapphire, has opted to re-design the PCB and has created a new twin-fan cooling solution to sit atop the brand new slice of graphical silicon.

Sapphire has also opted to clock its Radeon HD 7950 OverClock edition 100MHz faster than the reference model we've already reviewed.

That's not quite as fast as the AMD Radeon HD 7970's 925MHz, but it's certainly not far short.

In fact, in certain areas, it's actually better.

Benchmarks

The benchmarks don't lie and show the Sapphire Radeon HD 7950 OverClock edition is only a fraction behind the vanilla Radeon HD 7970.

Thanks to the impressive overclocking potential within the Sapphire card, and the AMD Tahiti core in general, you can easily push the OverClock edition to the same performance levels as the HD 7970.

All of these benchmarks were run at 2560x1600, with the overclocking results taken at the relevant card's maximum achieved overclock.

There's little between them at the very top end of the OC tree.

DirectX 11 tessellation performance

DirectX 11 gaming performance

Overclocking performance

Verdict

As good as the reference version of the AMD Radeon HD 7950 is, the Sapphire HD 7950 OverClock edition is just better.

Coupled with the awesome overclocking potential of the Tahiti core is an excellent cooling array with whisper quiet dual fans.

Being able to keep the temperature well below that of the reference card gives us far more faith in the longevity of the chip given a serious overclock.

That's a good job considering the excellent Trixx overclocking utility Sapphire bundles with the card.

That software is intrinsic to the extra performance we were able to wring out of the HD 7950 OverClock edition.

The AMD overdrive software runs out of track at 1,100MHz, while Trixx will allow us to push the card up to 1,300MHz and play around with the voltages to help us get close to the limits.

We quickly managed to hit a 1,170MHz core clock speed with the Sapphire sample we've been playing with.

And that's faster than we were able to push the Radeon HD 7970.

So the performance is excellent, on par with the top-end AMD HD 7970, and the cooling array makes for near silent graphical power play.

There's got to be a catch, right?

Well, we're still looking, but we'll be damned if we can find one…

At £360 it's only a tenner more expensive than AMD is recommending the reference design be sold for, and around the same amount cheaper than the rivalling Nvidia top-end card.

We say rivalling, but really there is no contest. The Sapphire HD 7950 is cheaper and knocks the Nvidia GeForce GTX 580 about like a tiger playing with a toddler.

Nvidia then has some work to do to rival this excellent card.

The only problem we can see has no real bearing on the end user at all and is only really an issue for AMD.

Nobody is going to want the HD 7970 now there's a card which is practically as good for over £100 less.

We liked

The raw performance of the HD 7950 is a known quantity now, as is its overclocking potential. With the Sapphire backing though it's an even better GPU.

There's also the power-saving goodness of the AMD ZeroCore Power technology which turns off most of the GPU when it's not needed.

We disliked

We're struggling to think of something negative to say here. Aside from the fact you'll only get the true value of this card with a big-screen, 2560x1440 or 2560x1600 monitor, there's nothing to say.

Verdict

Quite simply this is the only card we'd consider spending cash on if we were looking for a serious GPU upgrade.

Overview

AMD is really putting the pressure on Nvidia now with its second release of the new AMD HD 7000 graphics card generation, the AMD Radeon HD 7950.

Nvidia is still sitting back waiting for the right moment to strike back, but can it recover from these two quick blows?

Well, we say quick - it's been well over a month since AMD launched its first card of this generation, the AMD Radeon HD 7970.

That was a surprise given that, pre-Christmas, we were expecting both cards to hit the streets at the same time in the first week of January with a possible dual-GPU iteration coming around now.

AMD though decided to give its top-of-the-line, £500 AMD HD 7000 card a bit of breathing space at the start of its life, and now that the AMD Radeon HD 7950 is sat here in our labs it's easy to see why its release was delayed.

Essentially it's almost as good a card for over £100 less.

So AMD's claims to be delaying so it could wait for AMD Radeon HD 7950 units to be in the market (despite launching its big brother, the AMD Radeon HD 7970 well before you could even lay eyes on one) seem to be rather thin.

We think it's more likely AMD realised even fewer people would pick up a £500 graphics card when there was one for £350 that could do the same job practically as well.

To be fair though this isn't the first time this has happened; the previous generation had exactly the same problem in the two top-end Cayman cards – the Radeon HD 6950 and Radeon HD 6970.

There was precious little difference between the two cards in benchmarking terms, and with some judicious use of BIOS tweakery and ROM flashing fun, there ended up being precious little difference between them architecturally too.

But there must be some differentiating factors, some reason for the £150 price difference.

So, what has AMD chopped out of the AMD Radeon HD 7950 Graphics Core Next GPU to make the grade?

Architecture

The AMD Radeon HD 7950 is still based on the exact same Graphics Core Next/Southern Islands architecture as its only other AMD HD 7000 sibling, the HD 7970.

That means it's a graphics card still nailing the very latest of technologies in its rather sizeable package.

It's a fully fledged DirectX 11.1 card (though that's not actually going to be around soon, or even that big of a deal), more of interest though is the production process, shrinking down from the 40nm of the Cayman GPU to 28nm.

That's smaller than the current crop of CPUs.

That also means it can pack in a hell of a lot of those teeny transistors into the GPU, and AMD hasn't stinted. It's thrown 4.3 billion of them into this Tahiti core.

But it is a slightly chopped version of the Tahiti XT powering the AMD Radeon HD 7970.

This Tahiti Pro comes with only 28 of the Compute Units that make up the new vector processor AMD is now using for its graphics cards.

That means it's only rocking 1,792 shaders/Radeon Cores/streaming processors, or whatever you want to call them. Compared to the 2,048 of the Tahiti XT core that's a bit of a drop.

It also loses out on some 16 texture units, but thankfully it's still got the same full complement of ROPs at 32.

Outside of the GPU itself, the card as a whole comes with the same huge 3GB of GDDR5 frame buffer, on the same 384-bit interface.

And all still on the burgeoning PCIe 3.0 technology.

The clocks have also, inevitably, been cut back too.

The stock HD 7950 comes out of the box at 800MHz, a very conservative setting compared to the 925MHz of the HD 7970.

So, the AMD Radeon HD 7950 is not actually missing out on too much of AMD's new tech, indeed it's still hitting over 3TFLOPs of processing power to the HD 7970's 3.8TFLOPs.

For gamers though, forget FLOPs, it's polygon-pushing performance in games that we really want to know about. So how does that 20% drop in raw processing power translate into gaming benchmarks?

Benchmarks

At stock speeds the difference between the AMD Radeon HD 7950 and HD 7970 is actually quite pronounced, sometimes by as much as 25%.

That's a pretty reasonable performance difference between your top two GPUs, but it's not actually much to do with what's been chopped out of the GPU architecturally, more to do with the drop in clockspeed.

Once things are evened out in the core clock, through overclocking, there is suddenly almost nothing between the two AMD HD 7000 series cards.

The CrossFire performance is impressive for the AMD Radeon HD 7950 too, offering similar frame rates to the pricier cards, and the savings over the HD 7970 are multiplied in multi-GPU arrays.

DirectX 11 tessellation performance

DirectX 11 gaming performance

DirectX 10 gaming performance

Overclocking performance

CrossFire performance

Performance

As with any graphics card release it's all about performance and the AMD HD 7950 has got it in spades, and with a fair amount in reserve too.

At stock speeds the pace the AMD HD 7970 sets is tough for the HD 7950 to follow, leaving it at least 10% slower than its big brother. Sometimes that gap widens leaving the HD 7950 around 20% behind.

That's something that we would normally expect between the top two cards of a manufacturer's new generation.

But what of our assurances the AMD Radeon HD 7950 was almost as good a card?

Well as soon as you start waving around that familiar overclocking stick you can quickly see much of the difference between the two cards was taken up with the separation in core clockspeed.

Of course there's no guarantee that every Tahiti Pro GPU will be capable of these feats of overclocking, but the yields of these chips are only going to improve so I wouldn't be in the least surprised to see every Tahiti Pro capable of topping the 1GHz mark.

Like the HD 7970 before it we were able to drop into AMD's Overdrive software and push all the clock and memory sliders to their maximum settings without a problem.

In the case of the AMD Radeon HD 7950 that meant we hit 1,100MHz on the core and 1,575MHz for the memory.

That's fast.

And, as you can see from the benchmarks on the previous page, when the clockspeeds are pushed to the same limits there is almost nothing between the two top AMD HD 7000 series cards.

Considering the HD 7950 is over £100 cheaper than the HD 7970, that's quite impressive.

Interestingly though you don't even need to overclock the cards to make that difference disappear in CrossFire.

When the HD 7000 series cards are paired up there is again very little to separate them in terms of performance, and nothing that couldn't be closed if you just pushed the HD 7950 up to 925MHz.

Verdict

It's almost a shame AMD released the HD 7970 first when it could have had an instant hit, and a lot of good feeling over a month ago with the AMD Radeon HD 7950.

Though obviously people wouldn't have been quite so inclined to spend out for a HD 7970 when the cheaper card was just as capable a pixel-pusher.

But still, none of that can take away from the fact that the AMD Radeon HD 7950 is an excellent graphics card.

It's not just the AMD in-fighting that places this card at the top of the current crop of graphics cards.

We've been pushing the Nvidia GeForce GTX 580 as the go-to gamer's card since it was released, but the HD 7950 has that beat and for a good chunk of cash less than the Nvidia card.

And that's just at stock speeds. When you start overclocking this card the difference in performance increases hugely.

Even if you've never overclocked a graphics card in your life you owe it to all the engineers who worked on the Tahiti GPU to push it north of the 1GHz mark.

The reference cooler design, with its vapour chamber technology, is easily capable of absorbing the extra heat so the chance of causing any damage in doing so is negligible.

And all you need to do is bring up the AMD driver panel and push a couple of sliders.

Job done, instant, awesome frame rates.

Inevitably there are a host of factory overclocked Radeon HD 7950s on their way, like the Sapphire Radeon HD 7950 OverClock Edition, which will allow you to push the GPU even further.

The AMD HD 7950 could also be a massive hit for the CrossFire crew too, as for £700 you'll find yourself with an insanely quick graphics setup.

And for £300 less than an equivalent HD 7970 array.

Speaking of CrossFire too, it's worth mentioning that, like its big brother, the HD 7950 comes with the impressive AMD ZeroCore power tech.

That means if you've got a pair of GPUs running in your machine they'll only both be drawing power when you run a game. In normal desktop mode the second GPU switches off entirely, reducing power draw and unnecessary fan noise.

The primary GPU will also shut itself off almost entirely when the rig's screen goes into standby too.

For such power hungry gaming rigs these power saving functions are vital, and very, very welcome.

So AMD has got itself a real winner here with the HD 7950, even if it will inevitably cannibalise the sales of the pricier HD 7970.

We liked

The stock performance of the HD 7950 is impressive, but it's the amount of head-room for overclocking that Tahiti Pro core represents which really makes this card.

The ZeroCore Power tech is another of our favourite things about the HD 7950. Realistically you'll never notice it in action, but it will be there, saving you money unobtrusively in the background.

We disliked

The only thing to dislike about the card is the fact the clockspeed has been set so artificially low. Thankfully though AMD hasn't locked the overclocking possibilities down as it did with the HD 6950.

We did try flashing the BIOS of our reference HD 7950 to see if we could re-enact the fun we had unlocking the dormant cores in the Cayman GPU with the HD 6950.

Sadly while we were able to boot with the HD 7970 BIOS on the HD 7950 it didn't unlock the extra 256 Radeon Cores. And it didn't help with stability either…

Verdict

The AMD Radeon HD 7950 is one hell of an impressive pixel-pusher, and Nvidia is going to have to work incredibly hard with its Kepler cards to best this excellent card.

HIS has a reputation for employing unusual and efficient cooling solutions on its cards, and the HIS 6670 Fan 1GB GDDR5 is no exception.

This is its low-profile rendition of the HD 6670, AMD's lower-end gaming GPU. Granted, it's the type of graphics core that's hard to get too excited about, but while it struggles to produce triple-figure frame rates, at least it doesn't come with a triple figure price tag.

The low profile design brings home theatre PCs to mind, and it comes with extra brackets that can include or exclude the VGA output alongside the 3D-capable HDMI v1.4 and dual-link DVI ports.

The HIS 6670 Fan takes the full 1GB GDDR5 memory option rather than the cheaper GDDR3, and so has a decent 4GHz memory clock alongside the usual 800MHz core clock.

The GPU chiller comes in the shape of a dual 45mm fan cooling solution that proves to be far thinner than the stock cooler and far more elegant.

Theatre luvvie

As a low power, low profile graphics card, we can see the HIS 6670 Fan 1GB GDDR5 making a beeline for many home theatre installations. While it's certainly not a silent solution, its main advantage is the cooling efficiency of the dual-fan system.

Under continuous full load the GPU never breached 50°C while the automatic fan speed remained at around 40 per cent. HIS offers a silent solution with its HIS 6670 iSilence 4 1GB DDR3 as an alternative, but it only uses the slower 1.6GHz DDR3.

Fixing the fan speed to its lowest 20 per cent setting only raised the temperature a whisker to 50°C, therefore we think you could happily slap on a fan controller to further reduce this. Compare that to the Sapphire HD 6670 Ultimate which reported temperatures of 100°C under full load.

The enhanced cooling on offer here enables easy overclocking too. There were no signs of strain taking the core up to 900MHz and the memory up to 4,600MHz, which provided a 10 to 12 per cent increase in frame rates.

With the two low profile brackets provided, you can keep all three main video outputs active, with the analogue VGA output sitting next to its digital DVI and HDMI v1.4 friends. The v1.4 HDMI output is compatible with 3D displays, which means you can make use of the AMD HD3D technology.

TechRadar Labs

DirectX 11 tessellation performance
Heaven 2.5: Frames per second: Higher is better
HIS 6670 Fan 1GB GDDR5: 6.0
Sapphire HD 6670 Ultimate: 5.9
Sapphire HD 5670 Ultimate: 4.6

DirectX 11 gaming performance
AvP: Frames per second: Higher is better
HIS 6670 Fan 1GB GDDR5: 16
Sapphire HD 6670 Ultimate: 15
Sapphire HD 5670 Ultimate: 12

DirectX 11 gaming performance
DiRT 3: Frames per second: Higher is better
HIS 6670 Fan 1GB GDDR5: 24
Sapphire HD 6670 Ultimate: 24
Sapphire HD 5670 Ultimate: 21

Ultimately, performance is very slightly enhanced over other Radeon HD 6670 cards we've tested. The results may seem far from ideal for 1080p displays, but our benchmarks are run at the top detail settings with 4x AA. For example, shifting DiRT 3 from Ultra to High settings would see the frame rate double to a very playable 40fps or so.

HTPC purists may baulk at the fan-based cooling, but overall noise remained around the same as our test system's low-speed 110mm CPU cooler. Performance equals or exceeds that of other Radeon HD 6670 cards we've tested, but only just.

Overall, this is an excellent low-cost card with good overclocking abilities. Even so, we can't help thinking that it's not quite in the same class as the HD 5770.

Overview

So here it is, the AMD Radeon HD 7970 and, for the time being, it's the fastest graphics card around.

AMD has blinked first and opted to release its brand new graphics card architecture before Nvidia, and just before the new year.

It's a brave move by AMD though. Bringing out a radically different graphics design spec, compared with its previous vector processors, in the same year as it brought us a brand new CPU architecture.

Especially given the depressing failure of the AMD FX chips.

We've seen little bits from AMD about its new architecture, the plainly-named Graphics Core Next, before, but now it's humming away in our test bench and throwing pixels and polygons around our high-res screens without a care in the world.

Well, maybe the AMD Radeon HD 7970 does have some cause for concern considering Nvidia is set to launch its newest graphics architecture, code-named Kepler, in the early Spring of 2012.

Maybe that's why the timing of this release is so odd.

AMD has decided to effectively launch the Radeon HD 7970 just three days before Christmas, a notorious deadspot in technology news. We'll see the 'true' launch of the card, with the manufacturer's versions, coming early in the new year.

Though speaking with AMD board partners they're not allowed to release overclocked cards until well after launch.

So all they will be releasing are these reference Radeon HD 7970 cards with new stickers.

That means much of their thunder will be stolen by this here unveiling. And even that thunder will be deadened by the deafening silence of the holiday period.

So, like a junior cabinet minister in a time of crisis, is AMD trying to bury the launch of the Radeon HD 7970?

Maybe it realises the market for a £450 graphics cards is absolutely minute. Maybe the forthcoming Radeon HD 7950 is the card that it wants to really concentrate on. Maybe it just wanted to make sure us tech journos had to work right up to Christmas this year.

Whatever the real reason for this staggered launch is, it's time we took a proper look at what makes this here AMD Radeon HD 7970 tick.

Architecture

In terms of the actual make up of the AMD Radeon HD 7970 it's a fairly different beast to the previous, Cayman GPU-powered AMD Radeon HD 6970.

This card represents a new direction in GPU tech for AMD as well as a brand new production process and GPU technologies.

In terms of firsts AMD has them all pretty much nailed with the Radeon HD 7970. It's the first GPU to be built with miniscule 28nm transistors, the first DirectX 11.1 graphics card and the first official PCI Express 3.0 component too.

Of all those the really interesting one is the 28nm die shrink that comes with this new Tahiti core. The Tahiti GPU is going to be the chip powering the top end cards and that in turn is built on the new Graphics Core Next architecture.

The whole HD 7000 series also goes by the name of Southern Islands, hence the Tahiti tag.

That die-shrink means that it can jam more components into a smaller chip footprint and that should mean more power to you.

And compared to the number of 40nm transistors in the AMD Radeon HD 6970, a paltry 2.6 billion, it has done a good job of squeezing more into the Radeon HD 7970.

This card has 4.3 billion transistors in the GPU itself.

That there is a frightening number, and AMD has a lot more of those up its sleeve for the Radeon HD 7970.

AMD's claimed compute performance for the Tahiti XT GPU inside the HD 7970 is one such number. At 3.79 TFLOPs there is some impressive number crunching capabilities buried inside this chip.

All it needs is the software to take advantage of it.

The compute performance has been the driving factor in the change from Northern Islands to Southern Islands, and from the traditional vector style processor to the scalar processor that makes up this new GPU.

Previously AMD had focused most of its silicon towards the goal of making a card specifically for graphical processing, leaving the more ephemeral notion of general purpose GPU computing to Nvidia and its CUDA cores.

So it put all its eggs in the four-way vector processor architecture basket. Essentially that meant sorting out single instructions into batches before firing them down the GPU pipelines. It was a much more elegant solution and for doing fixed graphical processing it was incredibly efficient.

The resulting HD 4xxx thru HD 6xxx series cards were great pixel pushers at impressively lower power requirements than their peers.

Now though AMD wants a slice of the GPGPU pie and as such has shifted to a similar scalar architecture to that used by long-time rivals Nvidia.

That means it's going for a more brute force approach which involves having a large number of simple processors in an array, giving them each one thing to work on at a time until all the instructions have been completed.

The Graphics Core Next architecture then is built of Compute Units, which are similar in nature to teh Streaming Microprocessors Nvidia introduced with the Fermi architecture.

The Tahiti XT GPU in the Radeon HD 7970 is built up of 32 of these Compute Unites which are essentially self-contained processors capable of acting independently of the whole.

Inside each of the Compute Units are four vector units, and in each of those is 16 unified shaders or stream processors or Radeon Cores. Depending on who you talk to.

That means in the full Tahiti XT you'll find 2,048 shaders, and compared to the 1,536 shaders of the HD 6970 that's a fair mark up.

It's this combination of the four-way vector processing and the scalar architecture that AMD hopes will push its Tahiti-based GPUs to the top of the graphics card pile.

Though it's not just the number of Compute Units that makes the difference in performance terms, the actual core clock of the Radeon HD 7970 is far higher than previous cards too.

At 925MHz out of the box it's a chunk faster than the 880MHz of the Radeon HD 6970.

So, what do all these new architectural shenanigans mean for the graphics card's performance then? Let's find out…

Benchmarks

We've put the AMD Radeon HD 7970 through its paces in a raft of different benchmarks to see how it stands up against the competition.

The competition comes in the shape of the previous fastest single-GPU card available, the Nvidia GTX 580, and the previous generation of AMD's top single-GPU card, the Radeon HD 6970.

As these are the top of their respective lines we've pushed them to the max running all our benchmarks at the ultra-high, 30-inch panel resolution of 2560x1600 and all with 4x anti-aliasing too.

The results show a definite gaming win for the new AMD card, with the HD 7970 coming out on top in every single one of our gaming tests.

The two compute tests we used though don't really show up the enhanced computing power of the new architecture, though that's maybe more to do with the software not utilising the new silicon effectively.

Still, the GTX 580 seriously outperforms the new AMD card in the HD H.264 GPU encoding benchmark, though the HD 7970 has it beat in the Open CL-based GPU Caps Viewer test.

DirectX 11 tessellation performance

DirectX 11 gaming performance

DirectX 10 gaming performance

Open CL performance

Platform power performance

Performance

Now we come to the crunch then, the performance of this brand new slice of graphical silicon goodness.

It's quick.

Well, pretty quick.

The AMD Radeon HD 7970 has got the Nvidia GTX 580 beat hands down when it comes to raw graphics chomping, pixel-pushing, polygon-smashing performance.

In all of our gaming benchmarks the HD 7970 has the Nvidia card in second place, especially when you look at the particularly demanding Heaven 2.5 and Crysis 2 benchmarks.

With both those benchmarks you're looking at around a 30% improvement over the Nvidia GTX 580.

Those are the best case scenarios though as the performance benefits in the other titles are much less pronounced, sitting between 13% and 20% frame rate improvements.

When it comes to the previous generation, the venerable Cayman-powered HD 6970, things look better still. The HD 7970 posts a 65% improvement over the older card in the tessellation-heavy Heaven 2.5 benchmark.

That's the highest performance increase, but at worst it's around 25% faster. Ideally you'd be hoping for at least half again performance from a new generation, especially a die-shrink, but that can happen if you take things into your own hands.

This is all before you start waving around the overclocking stick then.

And boy, does this chip overclock.

In fact we ran into the limits of the AMD Overdrive software rather than the limits of the hardware itself. We pushed the card all the way up to 1,125MHz on the core clock and 1,575MHz on the memory clock.

With those numbers the performance increase over the GTX 580 and HD 6970 are way more pronounced with the HD 7970 beating the previous generation by up to 80%.

When overclocked too it gives the previous generation of dual-GPU cards, the Nvidia GTX 590 and HD 6990, a good run for their money. The GTX 590 had the highest score of 33FPS while the HD 7970 comes in just behind at 32FPS.

The HD 6990 actually lags behind it with 29FPS.

It's not just all about the raw performance figures though as AMD has made a lot of effort with the power requirements of the HD 7970, especially when running in idle mode, and with the screen off.

The ZeroCore Power technology means when the screen turns off and the machine goes into the 'long idle' state – where the PC is still running but there is nothing being updated on the screen so the panel goes to sleep – there is only a single chip on the card still running.

That chip is there just to tell the PC there is still a card in the PCIe slot and not to worry. The rest of the graphics card turns off completely, even the fan.

Verdict

We've accounted for the architecture and performance of the AMD Radeon HD 7970, but there is one thing we haven't covered, the price.

And that's key to the graphics card battle and in the case of the HD 7970 may well be the thing that truly buries it.

At approximately £450 it's quite frankly a ridiculously priced card.

It may well be the fastest single-GPU card around at the moment, but there is still little justification for the price.

Apart from the fact that a chip with 4.3 billion transistors, running on a new production process, is going to be rather expensive to manufacture that is.

There's also the question of whether you really need the levels of graphical performance the HD 7970 offers. There are very few of us out there running a monitor capable of the eye-watering resolutions of 2560x1600 so realistically a 1920x1080 resolution is going to be more likely.

And at that resolution the excellent £365 Nvidia GTX 580 is all the card you're going to need.

Even if we were going to give AMD the benefit of the doubt, and trust that it wont mess around with pricing across the Atlantic, taking the US price of $549 and the current exchange rate, plus VAT you're still looking at around £430.

That's still too much for a new graphics card these days.

How much is the forthcoming dual-GPU version going to cost? £700?

It's a shame, as if the card had come out at the same sort of price as AMD originally tagged the HD 6970 with it would have had a far better reception.

There are some good points about the HD 7970 the pricing cannot diminish however and that's because they will be rolled out across the Tahiti line.

That's the impressive ZeroCore Power tech.

Being able to shut the GPU down almost completely when idle is a great feat of engineering, made doubly so when you bring in CrossFire setups.

When in CrossFire mode all the GPUs will be in use when you're gaming, but when you drop down to 2D desktop mode all GPUs, bar the main card attached to the display, will shut down, fan and all.

That's impressive and means when you're using your monster rig in general computing tasks you're not going to require your own private Sellafield to power it.

The overclocking potential of the HD 7970 is likewise impressive.

We don't know the limits you can push this card to however as the software topped out before the hardware did.

Still we managed a huge overclock which makes us question why it wasn't rated as the first 1GHz GPU out of the box.

That though was answered by AMD's Director of Product Management for Discrete Graphics, Zvika Greenstein, at a recent tech insight event for the Graphics Core Next products.

"One of the things the enthusiast likes to do with our cards is overclock it, they pay a premium for that," says Greenstein. "We can position the HD 7970 as the fastest graphics card in the market at the reference clocks so we thought that we might as well leave it to the end users."

In essence, AMD didn't need to push the silicon, it's going to rely on the actual board manufacturers to do that themselves.

And they'll in turn charge end-user a premium for it.

We also had a few driver problems with the card too. We couldn't get any reasonable performance numbers out of the HD 7970 in our new Sandy Bridge E machine, with the benchmarks falling way behind the GTX 580.

It was only when we switched to our second AMD FX-8150 powered setup (the first blew up on the second benchmark) that we started to see proper performance numbers.

So in the end it's a tough ask for us to recommend going out and picking up the AMD Radeon HD 7970.

Especially when we know the Nvidia riposte is only a few scant months away. And according to Nvidia insiders it's quietly confident about its chances of the top Kepler card besting AMD's Tahiti XT-powered HD 7970.

Again then it's a wait and see game.

If Nvidia's card is even more expensive than the HD 7970 then this card may start to look like good value.

More likely the second tier Tahiti-powered Radeon will be the card that we really want to recommend.

Especially if it comes with the good parts of the Tahiti core, namely the ZeroCore Power tech and the heavenly overclocking headroom, all at a reasonable price.

We liked

The overclocking potential of the AMD Radeon HD 7970 is incredible.

Topping 1,100MHz is a huge overclock and makes it almost comparable to the previous generation of dual-GPU cards.

With or without an overclock though it is most definitely the fastest single–GPU graphics card around.

We disliked

Unfortunately the performance boost the HD 7970 offers isn't enough to really justify the vast price tag AMD has lumbered the new card with.

At this price it surely isn't going to sell in any volume.

The shadow of driver problems still loom over any new AMD graphics release too.

Final word

It may well be the fastest single-GPU card around, but the price is absolutely prohibitive. At £350 it would have been a hit, as it is we have no choice but to look elsewhere for a GPU recommendation.

Overview

You didn't think you were only going to get one version of the new GTX 560 Ti out of us did you? Always willing to push a little further here's Zotac's take on the new card, the Zotac GTX 560 Ti Limited Edition 448 Cores.

Now, in the Asus GTX 560 Ti 448 Cores Direct CU II review we've already spoken about how it's not really a standard Nvidia GTX 560 Ti at all, bar the nomenclature.

So we wont spend any more words discussing Nvidia's new marketing strategy for its old chips.

But there is another interesting facet to this new GTX 560 Ti's make up. And that's how the individual manufacturers create their cards.

Nvidia has made no reference designs for this chip and that means there are no hard and fast rules for the clockspeed settings.

And that, in turn, means the card manufacturers can release what are effectively overclocked cards straight off the bat.

Benchmarks

You can immediately tell the slight performance boost the out-of-the-box factory overclock gives you.

It's easy to assume from that the Zotac is the faster card but, while that is true at stock settings, the Asus card will easily outstrip the Zotac when you start waving the overclocking stick around.

DirectX 11 tessellation performance

DirectX 11 gaming performance

Verdict

So, in steps Zotac, it of the overclocked AMP! edition cards, with it's own up-clocked version of the GTX 560 Ti 448 Cores Limited Editon.

Compared with the Asus GTX 560 Ti 448 Cores Direct CU II version we've previously checked out this leaps out of the box with a 33MHz boost in clockspeed and a subsequently speedier shader clock too.

Granted that's hardly a lot to shout about in terms of clockspeeds, but it does give a nice little boost in the Heaven score.

If you're not much of a tinkerer and prefer to leave your graphics at their stock settings then picking up a slightly higher clocked card oput of the box is probably more your bag.

That rings true in terms of pricing too. This Zotac card is around £30 cheaper than the Asus version with its vast cooling array.

The only reason to opt for that Asus card over this one would be if you were looking to push the card as fast as possible.

The smaller cooling setup on this Zotac card cannot cope with the 900MHz speeds we squeezed out of the Asus board. That's not to say we couldn't get anything out of this more diminutive card; we were able to push it up to 850MHz stably, though rather warmly.

Speaking of size though, the Zotac version is a far more space-conscious offering than the massive Asus card.

It's shorter and, while still a dual-slot part, it should fit happier in tighter chassis.

Zotac's GTX 560 Ti 448 card actually ends up making a lot more sense than the Asus version.

At £250 the Asus version is only a little cheaper than the same cooler-heavy GTX 570 Direct CU II from Asus.

Essentially making it a complete irrelevance by comparison.

The Zotac card however fits in nicely between the standard GTX 560 Ti and the standard GTX 570.

We'd still recommend the faster GTX 570 at only £35 more, but if you're already struggling to scrape together £220 for a new GPU, and lets face it who isn't, then the Zotac card has a lot going for it.

It's almost the same speed as a true Nvidia GTX 570 and comes in cheaper. It's not quite as well designed a card as the Asus offering, but in price positioning it just makes a lot more sense.

We liked:

Coming with higher clockspeeds out of the box, and a lower price-tag to boot, makes this a far more relevant version of the limited edition card.

We disliked:

It's still only a little cheaper than the fully-fledged GTX 570, so if you can save a little longer that will give you much more for your money.

Final word:

A GTX 560 Ti 448 that makes more sense in such a crowded marketplace.

There are no new GPUs on the immediate horizon, but can Sapphire's Radeon HD 6970 Dual Fan edition make up for that? If you're into some freakish overclocking numbers then maybe it can.

The Cayman XT-based HD 6970 is the company's fastest single-GPU based card out of the box. But what if you want it to go even faster, how do you go about it?

Well, in the case of AMD's biggest board partner, Sapphire, you replace the PCB with your own design, build in improved power components, throw the reference cooler in the bin and replace it with a custom dual-fan design.

Then finally you tweak the twangers off the standard HD 6970's dual BIOS to offer a choice between normal and super-duper, voltage-crazy overclocking. The OC options allow access to higher voltages for the core, faster memory speeds and faster fan speeds.

The resulting HD 6970 Dual Fan Edition offers the choice between using the standard clock speeds (880MHz core, 1,375MHz) or, by flicking a switch, and using Sapphire's own TriXX overclocking utility, which is a good deal faster.

Keep pushing

What's important about this Sapphire HD 6970 is just how much farther can we push the card now that Sapphire has been delving around in it's design.

Out of the box, a standard HD 6970 has clock speeds of 880MHz for the core, while the memory trots along at 1,375MHz (5.5GHz effective), it's fairly speedy and will cope with any modern game with aplomb.

In standard mode with the card's reference voltage of 1.75v we got the Sapphire HD 6970 to run stably at an overclock of 965MHz on the core with the memory running at 1,497MHz (5.9GHz effective), which is pretty impressive.

Although in this mode the TriXX utility only allows a voltage of up to 1.2v. Thankfully through Sapphire's wizardry and the OC switch, we were able to test at 1.2 volts and above.

The secondary BIOS is all about the power tweaking. When the BIOS switch is in the normal mode, the PowerTune technology of the Catalyst Control Centre offers plus or minus 20 per cent. Switching over to the overclocking BIOS, this is boosted up to plus or minus 50 per cent to allow as much power to the card as possible. So needless to say we had to do just that to see what the card was capable of reaching.

The benefit of the additional power is that the clocks are not being throttled back by PowerTune. We managed to get all the benchmark games we used to run stably at 1,032MHz for the core (150MHz overclock) and 1,525MHz on the memory (150MHz for the memory). We managed 1,120MHz for the core and 1,528MHz for the memory, while still being able to boot stably into Windows. It wouldn't run the benchmarks stably but it did give an idea of the cards capabilities.

TechRadar Labs

DirectX 10 1080p gaming performance

Just Cause 2: Frames per second: Higher is better

Standard clock (880Mhz core): 53
Overclocked: (965Mhz core): 55
OC + 50% Power (1,032Mhz core): 61

DirectX 11 1080p gaming performance

DiRT3: Frames per second: Higher is better

Standard clock (880Mhz core): 66
Overclocked: (965Mhz core): 72
OC + 50% Power (1,032Mhz core): 79

DirectX 11 1080p gaming performance

AvP: Frames per second: Higher is better

Standard clock (880Mhz core): 49
Overclocked: (965Mhz core): 52
OC + 50% Power (1,032Mhz core): 60

DirectX 11 1080p gaming performance

Shogun2: Frames per second: Higher is better

Standard clock (880Mhz core): 51
Overclocked: (965Mhz core): 54
OC + 50% Power (1,032Mhz core): 59

So AMD's Cayman XT GPU is capable of impressive overclocking shenanigans then, but the credit must also go to Sapphire's heatsink and dual cooler design. It's amazingly quiet at normal speeds, only becoming noticeable as things get a bit hectic with some serious overclocking.

Overview

Asus is the first company to get this limited edition GTX 560 Ti 448 Core graphics card onto our testbench.

Now the dreaded limited edition tag has been handed to graphics cards many times over the years and generally it doesn't make for good things.

Most of the time, in the GPU world, it means a graphics card being thrown out to see how many of the general public will take the bait and pick up a hobbled version of a decent card.

Recent history has seen the fantastic GTX 460 getting that treatment with the GTX 460 SE in the November of 2010.

At a time when the GTX 460 was in great demand this slightly cheaper, weaker card hit the distributors and I'll wager a great many missed the SE tag in the name and simply thought they were getting a bargain.

They weren't.

Nvidia though, and by extension graphics card manufacturers like Asus, haven't taken the same route this time. The GTX 560 Ti 448 Core is not a hobbled version, in fact it's quite the contrary.

This new version of the GTX 560 Ti is a far superior beast than it's older sibling.

So what makes it so much better?

Architecture

The reason the GTX 560 Ti 448 Core makes good use of the 'limited edition' moniker is down to a much smarter bit of marketing than Nvidia usually uses.

Really this card is nothing like the old, vanilla GTX 560 Ti at all, in fact it's actually got much more in common with the GTX 570.

It's running the same GF 110 GPU instead of the GTX 560 Ti's GF 114. That gives it 14 of the streaming microprocessors to the other card's 8 and comes with a good chunk more ROPs. Eight in fact. It's also got a full 1,280MB frame buffer too.

If the GPU configuration of 448 cores, 56 texture units and 40 ROPs sounds familiar, you probably ought to get out more. That and you're probably recognising the layout of the original GTX 470.

So in essence this latest card is a hybrid of the GTX 470 and the GTX 570, and has little to do with the GTX 560 Ti that it's taking the name of.

That's no bad thing at all. If Nvidia had followed tradition and brought this card out around the holiday period calling it the GTX 570 limited edition we might have been baying for blood.

As it is we're far happier at the thought of a mainstream card getting some more technical loving.

Benchmarks

The Heaven 2.5 benchmark is a great indicator of raw graphical performance, and shows what the extra technical goodness of the GF 110 GPU offers over the vanilla card's GF 114 chip.

The Metro 2033 score is also a good indicator of DX11 performance, and also shows what the extra tessellation engines in the 14 streaming microprocessors offers the consumer.

These scores aren't far short of the GTX 570 and with the Asus card's impressive cooling the overclocking results can surpass it.

DirectX 11 tessellation performance

DirectX 11 gaming performance (2560x1600)

DirectX 11 gaming performance (1920x1080)

DirectX 10 gaming performance (1560x1600)

Verdict

In older titles the extra graphical hardware in the GF 110 GPU doesn't really add up to a huge boost in performance between the vanilla and 448 core versions of the GTX 560 Ti. When you look at the DirectX 10 Just Cause 2 we saw between 10-13% boost over the older card.

For the extra cash that's no great shakes, but when you look at more recent or more taxing titles, like Crysis 2 or Metro 2033, then things start to look more impressive.

In Crysis, in its full high-res texture and DirectX 11 glory, we saw improvements of 20%. That's in both the more standard 1080P resolution and at the eye-popping res of 2560x1600.

In Metro, while it still couldn't get above a single frame per second at 2560x1600, we managed to get almost a 50% boost in frame rates at 1920x1080 with 4x anti-aliasing – a notorious resource hog.

Part of the reason for this improvement at the higher resolutions is the extra graphics memory and the wider 320-bit bus.

The only issue, hardware-wise, is the knowledge that this is very much a stop-gap part.

It's a limited edition part because Nvidia is trying to ship out as much of its outstanding high-end chips as possible. If that means making them cheaper without impacting on the sales of the full high-end cards then that's alright.

The shelf-life then is limited as once this batch of GPUs has gone there wont be any more manufactured.

Nvidia is currently working on its range of next-gen Kepler graphics cards, which ought to come to light sometime Spring 2012. So that's its main focus right now.

AMD will also have its next generation of cards out early 2012 too, probably before Nvidia.

While it's always the case that the new range of faster cards is practically just around the corner, it still makes it tough to drop £250 on a card when that same money will probably get you much more in a very short space of time.

But still, you are getting a bit of kit that's only just shy of the excellent GTX 570.

And this Asus version is one hell of a proposition too.

It's redesigned PCB and power layout means that the Asus GTX 560 Ti 448 Core DirectCU II (phew) is an overclocking powerhouse too.

We pushed the GPU clockspeed up to the levels of the GTX 560 Ti (immediately surpassing the stock speed of the GTX 570 in the process) without the card breaking a sweat. The Asus GTX 560 Ti 448 Core actually topped out just over the 900MHz mark, a cool 170MHz over the stock clocks.

That overclocking prowess means it's also capable of taking on the vanilla Nvidia GTX 570 in a straight pixel-pushing fight.

The only down-side of the this Asus design is that, thanks to the chunky cooling solution allowing that insane overclocking, it's a triple-slot card. And that means you're going to need a likewise chunky case to house it.

The big issue though for this, effectively, slightly cut-down GeForce GTX 570 is that you can actually pick up a full GTX 570 for only a little more than the price of this hobbled version.

The enhanced cooling gives it a bit of an edge, but the triple slot GTX 570 DirectCU II is available for only £259. And that's the card we'd recommend over this one.

We liked

The fact you are getting a slightly cut-down GTX 570 for a little more than a standard GTX 560 Ti has to be a positive thing.

Coupled with the fact that Asus sure can design a graphics card's cooler, making for overclocking nirvana, makes that doubly so.

We disliked

As we've said, the only real issue with the hardware is the sheer size of that triple slot cooler. You will need a big chassis to give you space for everything else in your rig.

The major problem though is that it's too expensive considering you can pick up an actual GTX 570 for only a little bit more

Final word

A cooling masterclass by Asus, but the real GTX 570 can be picked up for around £260-odd.

Asus EAH 6770 DC: Overview

Asus has released the highest-clocked passively-cooled graphics card around in this, the Asus EAH 6770 DC.

And it's whisper quiet too.

There was a time, not too long ago, when if you wanted to build a silent or very quiet PC you knew you were going to have to sacrifice any notion of serious gameplay to get the quietness needed for the system you were building.

Well, helping to kick that idea out of touch, Asus has introduced the EAH6770 DC SL/2DI/1GD5. A really snappy name to remember that mouthful is.

No matter, the card combines AMD's HD6770 core with, it must be said, a pretty massive passive heatsink and cooling array.

It's created a passive card that makes a pretty good fist of playing today's demanding games even at high resolutions.

Although size-wise it's not a card for the more compact of PC cases.

Asus EAH 6770 DC: Benchmarks

As you can see from the test results the days of having to compromise between graphics performance over quietness are over, the EAH6770 DC SL/2DI/1GD5 suffers very little when compared to a normally cooled card (all be it with a non-reference cooler design) like Sapphire's Vapor-X HD6770.

DirectX 11 gaming performance

DirectX 10 gaming performance

Asus EAH 6770 DC: Verdict

On looks alone the EAH6770 DC is an impressive beast.

The passive dual slot cooler dwarfs the PCB it sits on to such an extent that should you have sausages for fingers you may find it a wee bit awkward to connect up the PCIe 6-pin power connector.

To give you an idea of just how big the cooler makes the card, the PCB itself is just 183mm long, while the whole thing measures 290 x 170 x 50mm, making it almost as big as some top of the range dual-GPU cards like the AMD HD 6990.

The cooler uses four 8mm Direct Contact heatpipes to dissipate the heat thorough the huge multi finned cooling array.

Direct Contact cooling just means that the heatpipes are flattened and form the part of, or as in this case the whole of, the contact plate instead of the pipes passing through the contact plate as in a normal design.

But having four such massive heatpipes in this case appears to be a bit of overkill as only two actually cover the diminutive Juniper XT core that the HD6770 uses.

Also helping to keep the card's temperature in check are the special alloy formula parts Asus has used in the cards power design.

Asus has left the core clock speed on the EAH6770 DC the same as the reference design; 850MHz while the 1GB of GDDR5 memory is clocked back a little at 1000MHz (4000MHz effective).

There's no down-clocking done to cope with the lack of active cooling which keeps this Asus card competitive. Performance wise the EAH6770 DC proves that a card being passively cooled doesn't have to have the life strangled out of it as it keeps pace quite happily with a normal, active-cooled HD6770.

The only real thing against the card is the sheer size of it, which rules it out of a lot of situations where a decent passive graphics card would be an ideal addition, for example in a small quiet/silent PC.

That massive passive heatsink on the EAH6770 DC does work extremely well though; even after a couple of hours using it to play Just Cause 2 at 1080p the heatpipes were hardly warm to the touch. Admittedly our test system is an open platform but even so that's some impressive cooling right there.

We liked:

The fact the Asus EAH 6770 DC is only a fraction behind a seriously active-cooled card like it's Vapor-X chilled brethren in performance terms is fantastic. That's a shot in the arm for the noise police.

We disliked:

The sheer size of the beast is a worry. With that massive passive cooling array taking up so much space this isn't a card you can drop into your small form factor living room PC.

Final word:

If you're looking for decent game play and silence from a discrete graphics card then look no more.