VR Zone compared Windows Vista 32-bit SP1 and the pre-beta version of Windows 7 on a Intel Core i7 965 based system and reports the upcoming Windows version was faster across all tests. The performance gains aren't huge but it's pretty impressive considering the operating system hasn't even reached beta stage yet.
We ran the Core i7 965 processor with ASUS Rampage II Extreme board at 4GHz and one HDD loaded with Vista 32-bit SP1 and the other with Windows 7 32-bit while everything else are identical. The Windows 7 allows Forceware 178.13 WDDM v1.1 drivers to be downloaded but we changed it to Forceware 180.44 WHQL drivers on both OS for fairer comparison. However, according to Microsoft graphics guidelines for Windows 7, WDDM v.1.1 Win7 drivers are supposed to provide reliability and performance improvements over the WDDM v1 Vista drivers although Vista drivers will work on Windows 7 too.
Forceware 180.44 WHQL drivers although works on Windows 7 but 3-way SLI is a no go for all games benchmarks and SLI doesn't work well on Far Cry 2. Therefore we ran a single GTX280 card for the Far Cry 2 test. The game tests are 3DMark Vantage, Crysis Warhead and Far Cry 2. We also test out SuperPI for the enthusiasts.
Moving from Vista to 7, we saw some performance improvements across all tests, although it isn't eye opening but decent enough. 3DMark Vantage "Performance" Preset is about 150 pts higher, SuperPI 8M is nearly a second faster, Crysis Warhead and Far Cry 2 register 3 FPS higher under 1280x1024 resolution, performance settings.