Todd will answer this specifically, but CUDA is not always equal to CUDA. There are different levels of the language and just like any hardware acceleration, specific features are dependent on specific capabilities like the number of ALUs/ shader units and drivers. it is reasonable to assume that CS6 will suppport more and different cards, but until then I wouldn't expect miracles. Combining different cards will not yield anything, most likely. If at all, multi-card environments work with identical cards since they require a unified driver so the cards can communicate and sync with one another. So safe the money, don't buy a Quadro..
You should also be made aware that AE does NOT gain much from a fancy GPU card, if indeed it gains anything. AE relies on lots of fast processors and lots of memory. You buy a good GPU card based on other applications' needs, not AE.
> when firing something like Premiere up (guess it's the same in AE)
The GPU features of After Effects and Premiere Pro are very separate.
Premiere Pro uses CUDA on certain cards, not including the GTX 590. See this page for details. If you want to request that the CUDA functionality be extended to the 590, then please submit a feature request.
After Effects uses OpenGL on any card with OpenGL 2.0, with specific features enabled depending on the capabilities of the card. See this page for details.
There's more in these movies:
> if i toss in a Quadro 4000 too will it work with three GPU's?
Premiere Pro will only use one GPU for CUDA computation. It doesn't, for example, use SLI to use multiple GPUs.
Thanks for you all your answers guys. Maybe not the answers I had hoped for but now I know the status of it. =)
Thanks again and have a nice weekend