I'm going to buy a new nVidia video card and, because of I'm very passionate of video editing, I want finally have one supported by Premiere Pro CS5.5. I've read something about that on the Adobe site, and I've found a list of supported GPUs:
Now I'm asking, if I bought a GTX 550, which is not in the list, would it be supported? I think so becase, however, it should be better than, for example, a GTX 470, instead present in the list. But I have this doubt... Can you clarify my ideas?
Welcome to the forums!
It depends on what you mean by supported. If you mean can you use either of them then the answer is yes. The supported list is those cards specifically have been tested by Adobe and are listed in the "cuda_supported_cards.txt" file If you have another card you may have to add it to that file. If you take a look at the Premiere Pro BecnMark (PPBM5) you will see that many other cards are being used by people that have submitted their results,
The more important factors that you should consider is the number of CUDA cores and how much power your system can supply to this upgrade that you intend to do. The 470 has 448 CUDA cores and requires 215 watts. The 550 is of course a slightly new design but it is at the low end of the CUDA cores with only 192 cores but it only draws 116 watts. Either could require you to upgrade your power supply depending on how much spare power is available in your power supply.
Here are some boards that I personally tested about a month ago (prices may have changed) showing PPBM5 (MPEG2-DVD, H.264 and Rendering the Timeline) encoding times versus board type.