Intel DZ77RE-75K review

A brand new Intel Extreme mobo with built-in Thunderbolt support

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  • Thunderbolt support
  • Twin PCI-E 3.0 slots
  • USB 3.0 ports


  • Not great performance
  • Some serious issues with Intel drivers causing BSOD

We've been here before, haven't we? Back in the days when we were used to having bespoke ports for every device, and plugging in something new involved powering down the entire PC and restarting before it would work, a brand new port with unassuming looks came along and changed everything.

When USB first arrived, you had to upgrade your hardware to take advantage of it. Motherboards and PCs that came with the new port would only have one, and devices that used it were expensive and thin on the ground.

Of course, that all changed over time, and USB ports and devices are now more plentiful, cheaper and a lot faster.

This is why there's a hint of déjà-vu with Thunderbolt. It promises a hell of a lot, but the cost and shortage of compatible devices mean that early adopters might want to tread carefully.

The new Intel DZ77RE-75K motherboard therefore can't rely on its Thunderbolt port alone to make it an attractive proposition. There are plenty of additional sweeteners to make it a more enticing upgrade, but are they enough?

Rolling thunder

Initially a joint collaboration between Intel and Apple, the Thunderbolt port combines PCI Express and DisplayPort functionality into serial data port. The upshot of this is an extremely versatile interface with data transfer rates of up to 10Gb/s, as well as the ability to daisy-chain up to six devices from a single port.

Thunderbolt retains backwards compatibility with DisplayPort devices, so you could feasibly daisy-chain six external hard drives and a monitor from one port. That looks great on paper, but does the Intel DZ77RE-75K capitalise on its potential?

We hooked up a LaCie Little Big Disk Thunderbolt external hard drive to the DZ77RE-75K in order to find out. In fact to really push the interface we popped two 120GB SSDs in a RAID 0 array into the enclosure. This certainly isn't the setup you'd usually get out of the box from LaCie - the Little Big Disk usually ships with dual 1TB hard drives ticking over at 7,200rpm.

With the two SSDs ready to hammer the Thunderbolt's bandwidth, we began running our data transfer benchmarks - and the results were very good, if not great.

With the AS SSD benchmark tool we saw sequential read speeds of 424MB/s, and write speeds of 250MB/s. The ATTO Disk Benchmark tool delivered similar results, with write speeds 273MB/s and read speeds of 466MB/s. This is a hell of a lot faster than USB 3.0, but a long way off the promised limit of 10Gb/s.

However, as we mentioned earlier, the LaCie Little Big Disk doesn't usually come with a pair of SSDs, normally you'd get a couple of 7,200rpm drives for your cash. If SSDs don't stress the interface, then traditional hard drives certainly won't, which leaves us with the rather large elephant in the room when it comes to Thunderbolt - there just aren't devices out there that truly take advantage of the technology.

Once you start daisy-chaining devices and streaming HD video from one storage device while copying large files to another - all while using a DisplayPort monitor - the increased bandwidth of Thunderbolt will prove useful. How often this scenario is likely to play out for you will be one of the main factors to consider if you're thinking of going for Thunderbolt.

We attached a second Thunderbolt drive to the Little Big Disk (most Thunderbolt devices should come with two ports for daisy-chaining) and the DZ77RE-75K detected it without a problem - it appeared in Windows Explorer as if we had plugged it directly into the motherboard.

While the ability to daisy-chain devices makes up for the fact that there is only one Thunderbolt port with the DZ77RE-75K, we wanted to identify any performance issues when doing so.

On the second hard drive, at the end of the chain, we ran a looped HD video file while running the AS SSD benchmark on the first drive again. The differences in the results were negligible, with only a slight decrease in write speeds (245MB/s - a drop of 5MB/s) and a tiny increase in read speeds (429MB/s, up just under 4MB/s). These results are within the margin of error, so we can say the performance impact is unnoticeable.

We then swapped the order of the drives, so that the drive playing the looped video was first in the chain, with our benchmark drive behind it. When we ran the benchmarks again the impact was much more pronounced, with read speeds of 210MB/s and write speeds of 394MB/s. Access times also leapt from 0.19ms to 0.26ms. This shows that the location of a device on the daisy-chain is worth considering if you're thinking about a similar setup.

Blue screen of death

While Thunderbolt certainly has potential - and it's a nice addition to the DZ77RE-75K - we don't think there are enough pros at the moment to justify purchasing the board for the new port alone.

So how does it cope in other areas? We've never felt that Intel Extreme boards were the sturdiest of mobos, and during our testing the DZ77RE-75K encountered a few hiccups, mainly to do with the integrated Intel HD Graphics 4000 of the Ivy Bridge processor (the i7-3770k fact fans) we were using.

With our monitor plugged in to the board's built-in HDMI, all was fine until we tried converting some video files, when our conversion program continued to hang. Updating the Intel HD Graphics 4000 drivers brought about a good old fashioned blue screen of death.

A quick trip into Safe Mode and rolling back the drivers did the trick, but there were a few more hangs in store for us, all based around the graphics. An Intel motherboard struggling with Intel's drivers for the integrated graphics on an Intel processor - hmm...

Elsewhere we get two PCI Express 3.0 x16 slots and the standard support for SLI and CrossFireX to help get around the flaky integrated graphics support. Dual gigabit LAN ports go some way towards making the DZ77RE-75K more interesting to us gamers, and there are enough USB ports in 2.0 and 3.0 flavours to shake a (USB) stick at.

Four SATA 6.0Gb/s ports complement the four 3.0Gb/s ports. It's a decent set of features, but nothing you won't find on any of the competitors' mobos.

As you'll see from our technical analysis, the performance of the board wasn't stellar either, lagging behind other boards - especially in the memory bandwidth stakes. In the end, the DZ77RE-75K's standard features and performance mean it ends up relying on Thunderbolt to stand out from the crowd. This early in Thunderbolt's life, unfortunately, that's just not enough.