Getting onto the machine's internals, as already mentioned the dual-core Intel Core 2 Extreme X9100 processor will stomp its way through most processor-intensive tasks and games, especially since it comes multiplier-unlocked to allow overclocking - though this is not usually a great idea on a laptop, and not necessary since games are held back by GPU rather than CPU power.
If you prefer four cores you'll have to move up to the £3,500 840SLI-QX9300, which will give you more future proofing, but at the moment the faster-clocked X9100 should give better performance in most games.
The CPU is backed by 4GB of 1,066MHz DDR3 RAM. While this is plenty for most, it would have been nice if Rock allowed you to upgrade to more memory, especially considering the power of the rest of this laptop and the 16GB maximum allowed by the installed 64-bit edition of Vista Premium.
We can't fault the X840's storage options, however. As standard, this Rock comes with twin 500GB hard drives running at a speedy 7,200rpm in RAID (with options for RAID 0, 1 or 5), giving you a total of 921GB formatted space. If this is not enough for you, you can add a third 500GB drive for £117, or if you want even more speed you can go for up to three 250GB solid state drives - though this will add another whopping £1,572 onto the price.
Talking of whopping, the aforementioned twin nVidia 280M GTX cards in SLI make for the most powerful mobile graphics solution available. Unfortunately, as with the speakers, you'll have to activate the second card yourself, since the Xtreme 840SLI-X9100 is set up as a single-card system by default. We noticed this initially because the performance in our gaming benchmarks was way below the expected level, and it's a severe oversight on Rock's part given less tech-savvy consumers might be confused by such a problem.
With that out of the way, how does this setup perform? For starters Call of Duty 4 ran at an average of 97 frames per second (fps) at the screen's native 1,920 x 1,080 resolution, with two samples of anti-aliasing and details set to maximum. This game gets a lot out of SLI, since the same benchmark with only one card enabled returned 53fps.
Regrettably the laptop that can run Crysis maxed out has yet to pass through our office, as even the £3,000 X840 couldn't quite manage it.
However, it certainly came closer than any before it, dragging in a barely playable 23fps at 1,920 x 1,080 on Very High Detail. When there was too much action things would drop down as low as 10fps though, so we had to turn the settings down to High Detail - on which the game still looks stunning - to get a smooth 31fps average (compared to 24fps with SLI disabled). Since Crysis is still the most graphically demanding game around, this Rock should run every other title out there at full detail with ease.
Wrapping up the impressive hardware list are Wireless Draft-N and Bluetooth 2.0. On the software front, meanwhile, we have a nice clean install - just the way gamers like it. All that's here is Cyberlink's PowerDVD to play back Blu-rays and Bullguard Internet Security, which generally doesn't have much of a negative impact on games even if you do leave it running. Rock also offers an attractive three-year on-site warranty as standard.