The current lack of support for next-generation features means that gaming performance between Windows 7 and its predecessors is relatively similar. Below is the summary of what's new in terms of gaming graphics in Windows 7. For the actual test results and full writeup - see the latest September 2009 issue of PC Authority magazine, on sale now.
DirectX11 and frame rates
Microsoft has been working hard on DirectX 11, which debuted in the Windows 7 Release Candidate. It isn't a brand-new graphics API such as DirectX 10 was; rather than building from the ground-up, Microsoft has refined and improved the last-generation software to try to ensure next-generation performance.
While this probably won't see frame rates jump overnight, several new features mean that the new API should be more scalable and efficient than the older software. Microsoft has concentrated on three broad areas for improvement with the new release: tessellation, multithreaded rendering and shaders.
Tessellation and poloygons
Tessellation was first introduced in the Xbox 360's Xenos GPU, and reduces the number of polygons used to render objects in the distance and then increasing the detail close up - in other words, using the same number of polygons to achieve more efficient results.
Multithreaded rendering is another area where Microsoft hopes to make the GPU more efficient. Much as desktop applications - including Photoshop CS4 - can take advantage of the multiple cores of a modern CPU, DirectX 11 enables graphical tasks to be handled by multiple processor cores too.
The third main boost has been given to the much-vaunted area of GPGPU (general-purpose GPU). Rather than having hundreds of shaders simply dedicated to graphics - the ATI Radeon HD 4870 has 800, for instance - DirectX 11 enables them to be used in other applications, such as the popular Folding@home research application.
These enhancements and any others planned for DirectX 11 are mere pipe dreams at present, though, because Nvidia and ATI's current-generation GPUs support only DirectX 10, although DirectX 11 cards are on the way.
Also see: The 30 Best Features of Windows 7