Gaming laptops

Although it's nice to have a PC large enough to house a quad-core CPU, a couple of graphics cards and a small army of hard disks, sometimes you want something smaller and more portable. A portable PC usually means a laptop, but the words 'small' and 'portable' are also often linked to 'puny' and 'weedy' and, as a Custom PC reader, you want a laptop with gusto and, crucially, the ability to play games.

The idea of a gaming laptop isn't exactly new, but manufacturers have only recently stopped shoving hulking desktop replacements in our faces and started to design laptops that are sensibly proportioned, yet optimised for playing games. Probably the single most important characteristic of a gaming laptop is the relationship between the screen size and the graphics processor. If the graphics processor doesn't possess the performance and memory bandwidth to render a smooth frame rate at the screen's native resolution, then you'll be forced to lower the resolution and accept the drop in quality that results from interpolation. On the flip side, a lower-resolution screen may mean that you can play games at the native resolution, but games and movies appear less cinematic.

In order to establish a level playing field, we asked several manufacturers to send us their best 17in gaming laptops. We decided to focus on laptops with 17in screens, as these give the best balance between visible screen area and portability. Smaller and lighter gaming laptops are available, but their screens are cramped, while a laptop with a screen larger than 17in will be too heavy to move around without a forklift truck.

So, if you've been looking for a performance gaming rig that can easily be taken to LAN events, or just into the garden, then read on.

Choosing a laptop is a more complicated process than choosing which desktop PC to buy. With a desktop PC, all you need to know is how fast and quiet it is, whether you like its looks and if you can afford it. When choosing a laptop, you also need to consider weight, battery life, how ergonomic it is, and the size and resolution of the screen.

To assess these factors, we designed a set of gruelling tests. The first comprises three games played at the native resolution of each laptop's screen. We chose three graphically intensive games, Oblivion, Colin McRae: DiRT and Company of Heroes, so that the results also indicate how well the laptops will cope with future games. This is especially important, as the vast majority of laptops can't be upgraded, particularly the graphics chip, so you'll be stuck with the same GPU in a year's time.

However, as some of the laptops we tested had very high-resolution screens, we also tested each laptop at 1,024 x 768. This might sound very low compared with the resolution at which you'd expect an equivalently priced desktop PC to be able to play games, but it's also the lowest resolution we use for testing gaming graphics cards; failing to play games at this resolution effectively means that the product isn't fit for its intended purpose.

We also tested the application performance of each laptop with our new Media Benchmarks 2007. These demanding tests evaluate the laptops' ability to edit high-resolution photos, encode HD video and run several applications in parallel.

Although laptops spend a lot of their time hooked up to the mains, it was important to compare the battery life of each laptop. As this Labs test is focused on gaming laptops, for which every MIP of performance is precious, we started by disabling any advanced power management features, so that the CPU and GPU worked at full throttle. We then played Oblivion while running a script in the background that wrote an entry into a log file every minute until the battery died. The results from this test can be found along with all the performance benchmark data on p87.

In addition to gaming and application performance, we evaluated the TFT screens' image quality by watching several HD movie trailers. Although this is a subjective way of testing screen quality, as we were comparing all the laptops with each other, we consider it to be a fair assessment. The HD movie trailers allowed us to evaluate the sound quality of the integrated speakers and, interestingly, they also highlighted the massive difference in maximum volume levels too.