The rockdirect Xtreme SL is one of the first laptops to use two graphics cards. It sounds the death knell for the days when laptops were perceived as poor gaming devices, and is part of a new breed of laptop that uses a 19-inch screen.
The Xtreme SL is available from rockdirect via their Web site. We tested the basic version, which costs £2,349, but this is customisable online.
The rockdirect Xtreme SL is fairly ugly -- especially in comparison to the similarly sized . It's finished in a rather dull grey colour with a contrasting black keyboard, but it's difficult to identify anything remotely stylish about it.
To its credit, the laptop includes a (nearly) full-size keyboard. There's even a dedicated number pad, but this is positioned uncomfortably close to the main Qwerty section for our liking, and the half-size return key can be fiddly to press when touch-typing.
One area that's difficult to ignore is the Xtreme SL's build quality. The entire keyboard flexes dramatically during use, and emits an unpleasant hollow echo when you tap its keys. The keys themselves feel flimsy and the screen bezel doesn't seem correctly fastened, but rockdirect assures us these problems aren't present in final retail samples.
It's not all bad news, though. The polished silver shortcut keys above the keyboard look fairly smart and the circular speaker ports on either side of the unit make a good visual, if not aural, impression.
The Xtreme SL is based on an AMD Athlon 64 Turion ML-42 processor. It's not one of AMD's newer dual-core mobile CPUs, but rather an older model, originally aimed at countering the threat of the now ageing Pentium M. It runs at a respectable 2.4GHz, but despite its high clock speed it isn't as efficient as the newer dual-core Turion CPUs.
Our review sample was supplied with 1GB of DDR400 memory -- a high enough quantity of RAM for most tastes. Hardcore gamers, however, and anyone who likes to indulge in heavy image or video editing, would be wise to customise the laptop with an extra 1GB of memory. This is available on rockdirect's Web site for an extra £147.
Most of us will be impressed by the twin graphics cards at the heart of the system. rockdirect has chosen two Nvidia GeForce Go 7800 GTXs running in a Scalable Link Interface (SLI) configuration in order to maximise the laptop's gaming abilities. This is an inspired choice of card, as even a single Go 7800 GTX delivers miles more 3D horsepower than the integrated graphics solutions in most laptops. The Go version of the card is largely identical to those you'll find in high-end gaming desktops, but has a slightly lower memory bandwidth and pixel-fill rate.
The Xtreme SL's native screen resolution of 1,680x1,050 pixels hinders it somewhat. Its 16:10 aspect ratio is fine for watching widescreen movies (which typically have a 16:9 ratio), and provides acres of desktop space for viewing multiple windows side by side, but it's not always ideal for gaming, because most games run by default in a 5:4 or 4:3 aspect ratio. As a result, the laptop will intelligently scale (stretch) the game image to fit its screen, blurring it slightly in the process
The highest 5:4 aspect ratio resolution possible on the Xtreme SL is 1,280x1,024 pixels. This simply isn't high enough to make the most of the laptop's twin graphics cards -- as you only really see the benefit of SLI graphics when running at higher resolutions with special image-quality effects, such as anti-aliasing (AA) and anisotropic filtering (AF). It is possible to make some games run at the native 16:10 aspect ratio at the laptop's preferred 1,680x1,050 pixel resolution, but you'll often need to edit a special configuration (.cfg) file to do so.
To its credit, the laptop's screen delivers images of a good quality. It's not quite as impressive as that of the Samsung M70, but it uses X-Glass coating to increase the level of contrast and detail, and it's great for watching DVD movies on.
The Xtreme SL produced an impressive performance in most aspects. It proved only marginally slower than the all-conquering in common desktop and office productivity applications, achieving a PCMark 2005 score of 3,930.
3D graphics performance was even more impressive. At its native resolution of 1,680x1,050 pixels it clocked up a 3DMark 2006 score of 5,013, and was slightly quicker at 1,280x1,024 -- reaching 5,444. These are the highest scores we've seen for any laptop.
These achievements were mirrored in real-world gaming tests. Doom 3 ran at 98.4 frames per second at 1,024x768 pixels and 94.7fps at 1,280x1,024 pixels. When we applied 4x AA and AF at the same resolutions, Doom 3 ran at 94.4fps and 86fps respectively.
Only when cranking the eye candy up to 8x AA and 16x AF at these resolutions did the Xtreme SL begin to slow signs of graphical fatigue. It achieved 81.6fps and 61.6fps respectively -- but these are excellent scores, and again, are the fastest we've seen from any laptop to date.
Edited by Mary Lojkine
Additional editing by Nick Hide