Rainbow six on pc is an example of the "throw more cpu cycles at it" way of programming.
Its a growing trend .
Programmers once cared how many cpu cycles they were using, how much memory, and would hand optimize parts of code to make it run better.
Now programmers tend to use the "PC hardware just hasn't caught up to us" excuse.
Thats why you can play some games and the graphics and framerate is great, and then you play something like rainbow six on the pc and go wtf ?
I think supreme commander also suffers from this.
You mean I can use my pc with 3d studio max, running havok physics caclulations with 32,000 particles and 2 million polys, but it can't calculate the units in supreme commander fast enough ?, Uhm yeah
Its not your pc, its lazy programmers.