I don't really feel like timing every thing the game does, so I'll just show my specs:
Pentium 4 CPU 3.20GHz
ATI Radeon HD 3650 (AGP)
2GB RAM DDR2
OS: Windws 7

Have the game completely maxed out, except for the high quality houses, it is set to 4. The game runs well, playable FPS, don't really knw the number, but at least for me it runs perfectly, it only hangs when going to the neighbourhood view.

I have the very latest awesome mod, should I install ISM now?

I am also using Win7 and the Sims 3 runs just like it runs on any other Windows.

Riverview is free, so if annyone manages to download it share it as soon as possible!