Updated: read our Windows 7 review, plus, now it's been released, our full comparison:
Even now, it's hard to think of a single killer app that makes DX10 look any better than the huge swathe of DX9 games. This is why there are still plenty of people out there who are running their games under Windows XP. Add Windows 7 into the mix and you now have a three-way fight for your gaming attentions. But which one should you have running on your main gaming rig?
The reliable Windows XP, the pretty but oft-maligned Vista or the new kid on the block who hasn't even earned his racing wheels yet? We think it's time to put these operating systems to the test on a suite of benchmarks and see which one impresses us the most.
How we tested
In order to assess how these operating systems perform on a mainstream gaming PC, we've elected to torture a Dell for your delectation. The Studio XPS M435T we've picked boasts a Core i7 920 at its heart and 6GB of DDR3 1066MHz triple channel memory, making it a serious number cruncher when given room to strut its stuff.
Things aren't quite so carefree in the graphics department though, and in order to hit a decent price point (the machine can be picked up for around £700) it features a single 512MB GeForce 9800GT. Not a gaming powerhouse, but a capable enough performer for our testing.
For the benchmarks we've focused on gaming, putting Codemasters' seminal GRID, Ubisoft's brilliant Far Cry 2 and the splendid RTS-'em-up World in Conflict to task separating the OS wheat from the chaff.
GRID boasts a brilliantly optimised rendering engine, which shouldn't push the hardware too much. Far Cry 2 is taxing with all the features turned on and requires just as much rendering muscle as processing power. World in Conflict shows off the differences between DX9 and DX10 rendering and is one of the most reliable benchmarks we've used in the office.