Before even considering this question, I need to point out to you that the GPU is not very much relevant to After Effects.
After Effects can use OpenGL to accelerate rendering, but the fidelity isn't perfect with the rendering that is done on the CPU, so OpenGL rendering is really just useful (if at all) for previews.
Personally, I leave OpenGL rendering off and only have OpenGL - Interactive on for previews.
So, don't waste time thinking about the GPU regarding After Effects.
Isn't perfect? You mean quality of final rendering?
> Isn't perfect? You mean quality of final rendering?
The OpenGL renderer can't render everything that the CPU renderer can. That's why the OpenGL renderer is recommended for doing fast previews only. See the "Render with OpenGL" page for a list of what the OpenGL renderer can render.
OK, I understand. But if we have something to render that OpenGL fully support what is the most important parameter in graphic card for rendering performance?
For AE ? None. Even if you render with OGL, AE won't use much of your Card. Avoid Dual proc cards like the Ati x2 because it will confuse and crash AE (and you'll have to manually diable one of them before rendering).
To be honest, never render with OGL in AE. You'll be faster 99% of time with software rendering, because OGL render kills multiprocessing, so in the end 1core+OGL is most of time slower than 2/3/4/x cores+software.