I'm not sure that's even possible. AE can use OpenGL for preview and final rendering, but I've never heard of it providing meaningful speed bumps simply because you can't use "render multiple frames" at the same time as OpenGL final rendering. Therefore, it's almost always a wash or a major speed decrease to do final renders with OpenGL.
Perhaps the old video card was causing some sort of conflict or other issue with his computer's processor, preventing it from being used to it's fullest for AE, and he would have experienced a similar bump in performance if he had merely removed it.
- The Great Szalam
(The 'Great' stands for 'Not So Great, in fact, Extremely Humble')
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