Does anyone know how to get an idea of what sort of contribution different GPUs can give? I'll be setting up a few PCs from socket 1156 and later and socket AM2 and later soon, and need to buy low end or mainstream GPUs for them. For AMD platforms, I'm thinking of something like HD 77x0 cards or slower (and cheaper - to set up several systems, GPU price is initially a major factor), and for Intel platforms I'm considering GT 720/730, maybe slightly higher. Anything that is too slow for folding will be used for wcg.
I'll also be setting up other, older systems for testing purposes, but most will be no good for folding or wcg.