How to know what video card supports QE/CI (32/64bit?)

Based on my experience, the max version of OSX that supports QE/CI ie:

For Nvidia

10.5 32bit - 5200FX
10.6 32bit - 6200, 6600, 7900
10.7 64bit - ???

For ATI

10.5 - 2400HD

How does one know this info? besides trial and error?
This would help in a "Video card buying guide"

ie: why 10.6 not support 5200FX.

Again, I only mean QE/CI, not resolution change...