The reason that ATI cards are slower in Vue is that they use a software emulator for some functions that nVidia has as hardware. These functions have to do with geometry processing, so nVidia cards are almost always more efficient and often faster than ATI cards for applications involving 3D. Of course, a more powerful ATI card will offer greater performance than a cheaper and older nVidia card, as a general rule.

CUDA processes do not equate with "threads" or anything else, really. CUDA refers to a way in which certain physical phenomena, such as particles or object dynamics (fracturing stones, for example) are processed by the GPU on the video card (that is, off-loaded from the motherboard CPU). It is a proprietary process belonging and exclusive to nVidia cards. There is no equivalent in the ATI chipset or for any other video card maker. (Hope this attempt at "plain language", non-tech talk is understandable.) I do not know if the particle processes or the new ecosystem/particle processes in Vue 11 make use of CUDA processes on nVidia cards or not. Perhaps someone else on this Forum does know.

For this reason, CUDA being a set of GPU processes that Vue may or may not use in any meaninful way, I agree with aeilkema's comments that it might not be good to go from a 256 bit processor to a 128-bit processor.  However, given that the CPU described above is kind of a mid-range i5, any upgrade to an nVidia card with a good GPU will pull some of the load from the cpu and pass it to the cpu, and that is all to the good. Having more video memory, then is a good thing. So, there should be some real measurable and significant increase in processing performance from the proposed upgrade. Not as much as we would expect to see on an Intel i7 cpu, but nevertheless, some serious increase in performance.

Given that what is being basically proposed, in technical terms, ... transferring a significant amout of processing from the cpu to the gpu, kenmo also has to take into account the motherboard. He has not told us what that is, but it very much matters here. A run-of-the-mill motherboard could be the bottleneck that makes this upgrade less significant than it might be. Or, kenmo could have a very good motherboard, which will make the proposed upgrade everything that should happen with the change.

 post query... I did some tech checking. Vue does not make use of CUDA. So the whole thing being accomplished by the proposed upgrade is to offload some processes from the motherboard cpu to the gpu on the nVidia card. Still, this is an upgrade that makes sense to me.

Kenmo, you also need to make sure that you have sufficient power for the new nVidia 650 card. The stated power wattage requirement is 500 watts for the card alone, but one of my computers has a nVidia 650, and I found that I needed to allow the card to have at least 650 watts to itself. In my case, I had to upgrade the power supply on that box to a 1000 watt psu, a first for me!