VRAM doesn't necessarily work that way. A video frame is only so big, and the plug-in may or may not be completely optimized for your graphics card or the current version of your drivers. I'd check with the Element 3D folks. This is probably not directly an AE issue.
Thanks Rick, I posted in the Element 3D forums. Hopefully they can help to shed some light on this too. I really can't complain though. I can do all of my 3D modeling in real time now which is all that matters to me. I'm just looking towards the future with my projects. Eventually that untapped VRAM may be required... eventually
So, this topic started as a side topic in a separate thread. I started this thread to separate the two somewhat unrelated topics so people looking for answers to similar problems could find them easier. Here is the link to that thread: http://forums.adobe.com/message/6247774#6247774
Some relevant comments went back and forth between Todd Kopriva and myself so I'm adding those here.
Todd asked what my texture memory was set to in After Effects preferences.
I changed it from 200MB to 2000MB (the max I could set it to) and restarted After Effects, but it didn't make a difference. I then posted the following image to verify that I did indeed change the correct settings:
That's where the conversation left off. Does anyone else have any other ideas?
Alright, so I've done some more tests and I found out that I had to set the fast previews to Adaptive Resolution -- Open GL Off. Now my GPU stores up to exactly 2GB (the value I set my texture memory to). So it looks like if I can set my texture memory higher I'll also be able to take a greater advantage of my GPU. However, After Effects CS5.5 won't let me increase the texture memory any higher than 2000MB. Is there a workaround for this or is After Effects just not capable of using more than 2GB of VRAM?
Edit: Did some more tests. For some reason 2GB seems to be the limit for 1080 video, but bumping up to a 4K comp got me to 4GB very quickly. So it looks like the high quality 3D models I was adding didn't take up as much VRAM as I thought they would. Even better than that is after changing the fast preview to Adaptive Resolution I can now have 1000 low to medium poly count models and move around the scene in real time, no lag at all. Still not sure why having Open GL on causes things to slow down so much though. Maybe because Element 3D uses their own Open GL renderer and the After Effects Open GL renderer starts to conflict? No idea, either way I'm far more than satisfied with my findings.
Edit 2: Ran some tests with a 4k aircraft model in a 1080 comp. It takes about 1.5GB of VRAM to load it, but once I run a RAM preview it takes up 3.5GB. Looks like it all depends on the models you use in your projects. If you aren't using crazy high res/polycount models then you'll be fine with 3GB, or maybe even 2GB of VRAM, but as soon as you start using high res models, especially high res models of very large/complicated models like large planes, people, cars, etc. then more VRAM definitely makes a difference. I hope this helps someone else down the road!