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Verdict
Fastest graphics card money can buy.
Says it all doesn't it? Therefore it must also be the bestest too. Everyone loves it, AMD will sell out of all its stock and we can all go home knowing that graphics cards have reached their zenith.
Would that it were, dear reader, would that it were…
Unfortunately a number of things have conspired to make the AMD Radeon HD 6990 not quite the graphical giant AMD hoped it would be.
When AMD first started down the road of multi-GPU, single cards, its CrossFire technology wasn't widely trusted, and also didn't give the sort of nigh-on 2x performance increase we felt the extra outlay deserved.
Back then a single card that took much of the driver-related hassle out of a traditional CrossFire setup was almost inspirational. Now a CrossFire setup isn't beyond the reach of most of us, and paying the same sort of price for a generally faster HD 6970 setup makes more sense.
This is where it gets tricky for the HD 6990 you see.
A pair of HD 6970s beats it in performance terms unless you invoke the mystical Antilles Unlocking Switch. But there is no guarantee that will work with your power supply, no matter how many PCIe plugs you've got trailing out of it like some many-tentacled Cthulu.
In order to power the HD 6990 in full-fat Cayman XT mode your PSU needs to have a clean delivery of juice to the motherboard and card and be happy to fire 450w down its pipes without slipping up.
AMD wont guarantee the functionality of this second BIOS, so unless you know for sure your PSU can hack it then you really need to look at it in terms of the stock performance.
And, as we say, there the HD 6970 in CrossFire has it beat.
This is all before we even think about the BIOS tweakery you can do with a reference HD 6950 and its own dual-BIOS switch. A pair of reference-design cards will set you back just £440-odd and even running at stock speeds will deliver performance very close to the HD 6990.
Take the minimal risk of flashing the second BIOS chip with a HD 6970 ROM and you've got it beat for over £100 less cash.
Bargain.
So is there any reason to bag yourself a Radeon HD 6990? To be fair, no. At the moment AMD can say that they have, without doubt, the fastest graphics card available. That's a nice thing to say, but is almost irrelevant given the price and performance of its CrossFire cards.
If the HD 6990 was cheaper than a pair of HD 6970s then it would be worth a look – it's not as fast and so a little saving would go a long way. As it is it's an awful lot of pennies for a setup you can create yourself for a lot less.
And then there's Nvidia.
It has stayed very quiet about the forthcoming GeForce GTX 590, leading us top believe it was waiting to see what price the HD 6990 tipped up at, and how it performed.
If reports are to be believed and the GTX 590 is packing two of the GF110 from its GeForce GTX 580, then it's going to absolutely hose the poor HD 6990. But then it could also be the most expensive graphics card anybody has ever seen…
So the Radeon HD 6990 may be the fastest graphics card around bar none, but that situation may not even last out the month.
We liked
The fact AMD has created a single card housing this much graphical horse-power is truly impressive and it does offer some serious performance chops.
The Antilles Unlocking Switch also allows it to behave just like a standard top-end AMD CrossFire setup, something the previous generations of multi-GPU cards couldn't offer.
We disliked
Unfortunately AMD has priced its Radeon HD 6990 out of the market with a price-tag that's at best the same as a pair of HD 6970s, for generally less performance.
It's also far too expensive considering the relative cost of a pair of reference-design HD 6950s, and all the BIOS tweakery those brilliant cards offer.
I also have some reservations about the cooling setup. I understand the need to have the centralised fan blowing air equally across the twin GPUs but it is expelling an awful lot of heat directly into your PC's chassis.
It's got one hell of a footprint too, making it far too long for a majority of gaming cases.
Final word
Despite taking the fastest graphics card in the world title, it's just not a particularly desirable card.
