Im guessing a high end dual core part (core 2 duo or quad core) and 2Gb of RAM is essential for gaming on vista and keeping frame rates high, a mediocre CPU is not going to be enough right now due to games still requiring a lot of CPU cycles.
Naturally as the hardware gets faster and the games require more the % difference between the OS's will shrink below the % difference between the API's and we'll see the benefits. Bare in mind that this might not be as fast as you expect, like with previous OS's we can expect the slew of MS patches and service packs to slow the OS down over time.
Naturally as the hardware gets faster and the games require more the % difference between the OS's will shrink below the % difference between the API's and we'll see the benefits. Bare in mind that this might not be as fast as you expect, like with previous OS's we can expect the slew of MS patches and service packs to slow the OS down over time.