See something familiar? That's right, the Rock Xtreme 685 is yet another re-badged Clevo whitebook. On the downside, that means the styling is about as exciting as a Conservative Party Conference speech delivered by the Under-secretary of Dullness.

For a 15.6-inch notebook, the Xtreme 685 is a big old thing, too, with a hefty power supply. Put the two together and you have a dreary looking lump that's also a pretty unpleasant package in terms of portability.

Appearances, however, are deceptive. This thing shifts. Partly, that's because it's got one of the most powerful processors currently available for a laptop. The Intel Core i7 2820QM is not only clocked a little higher than the quad-core competition with a 2.3GHz nominal clockspeed and 3.4GHz Turbo.

It also packs 8MB of cache memory where the Core i7 2630QM makes do with 6MB. All in, it makes the 2820QM about 15 per cent faster than the 2630QM.

In store Rock has also made an effort regards storage performance in the form of a pair of conventional magnetic 500GB hard drives in RAID 0. We'd rather have a smallish SSD and a large conventional drive, frankly. But as spinning magnetic platters in laptops go, Rock's RAID'ed effort is about as good as it gets.

However, the real weapon in the Xtreme 685's armoury is the AMD Radeon HD 6990M. It's the fastest mobile GPU on the planet.

Just get a load of these stats: 1,120 shaders, 56 texture units, 32 ROPs and a 256-bit memory bus. No wonder the rendering and gaming performance is epic. The HD 6990M tears Dirt 3 a new one, even running in full HD.

But more impressive are the results in World of Conflict. It's a great title for getting an idea of overall gaming performance thanks to heavily loading both the CPU and GPU. Get the balance of components in a laptop wrong and the result can be a system that spits out decent average frame rates in the WiC benchmark but scrapes the barrel in terms of the minimum frame rate.

But not the Xtreme 685. Running at 1,920 x 1,080 and with 4x anti-aliasing enabled, it cranks out an average 51fps and a minimum of 32fps. The latter, critically, is above 30 and that means smooth gaming at all times.

TechRadar Labs

tech labs

Rendering performance
Cinebench R10: Seconds: Quicker is better
MSI GT780 DX: 51s
Rock Xtreme 685: 46s

Battery life performance
Battery Life: Minutes: Higher is better
MSI GT780 DX: 141
Rock Xtreme 685: 108

DX11 gaming performance (1,280x720, 4x AA)
Dirt 3: Frames per second: Higher is better
MSI GT780 DX: 102
Rock Xtreme 685: 108

Industry standard 3D performance
3DMark 06: Index score: Higher is better
MSI GT780 DX: 16,634
Rock Xtreme 685: 20,497

DX10 gaming performance (1,280x720, 4x AA)
WiC: Frames per second: Higher is better
MSI GT780 DX: 57
Rock Xtreme 685: 74

Tessellation gaming performance (1,280 x 720, 4x AA)
Heaven: Frames per second: Higher is better
MSI GT780 DX: 28
Rock Xtreme 685: 40

rock xtreme 685

Of course, all of the above applies to current titles. Scope out the frame rates in the Heaven benchmark and it's clear any future games heavy in tessellation effects aren't exactly going to fly. And like nearly every laptop, upgrading the graphics card is a non-starter.

Finally, a word on the LCD panel. Thanks to the 15.6-inch diagonal and full-HD 1,920 x 1,080 native resolution, the image quality is super sharp. However, the panel is of the TN variety and it's never going to match a VA or IPS for colours, viewing angles or contrast.

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