A review of supposedly DirectX 10-enhanced game Gears of War found there was "no difference" in image quality than running the game in the older DirectX 9.
DirectX 10 is Microsoft's new graphics platform, designed for Windows Vista. It's not available on Windows XP, though rumour after rumour has suggested it might be.
Who needs DX10?
"We found no image quality differences," says Brent Justice, writing on HardOCP's Enthusiast channel.
"But we did find a large performance drop on every video card. Simply put there is no reason to run this game in DX10 unless you have a powerful enough video card to handle 4X AA [Anti-Aliasing] with this mode enabled." 4X AA is a DirectX10-only option in the game, so you'll need something from Nvidia's GForce 8-series or ATI's HD 2000 line.
When DirectX 10 was first announced, it was clear that Microsoft would use it as a tool to force enthusiasts to upgrade their machines to Vista. But it hasn't worked, with review after review giving a lukewarm response to both DirectX 10-enabled graphics cards and games.
Just turn it off
"For the best performance, run this game with DX10 'off' and crank up the resolution with maximum in-game settings for a very fun, fast paced, action game," says Justice.
The review is positive about the game though, describing it as a "a non-stop barrel of action delivering a unique gameplay experience".