Double-check your After Effects Work Area, which is seen at the very top of the AE timeline. It sounds like it may be set to 30 seconds. AE defaults to rendering the Work Area.
Hi Dave...I reduced the work area from 6 min to 1:30, but still will only render the first 30 seconds. I changed the Preview to start From Current Time and again it will render about 30 seconds from the playhead location on the timeline.
Side question: I need to edit to the audio...how can I scrub through my audio while setting key frames for other objects?
Found the answer to the Side question....Ctrl + click and drag will scrub thru the audio!!
AE does not use the video card for acceleration. The 640 is quite good for AE, no need to waste money on a new video card, that is not used at all.
Speeding things up in AE means more cores, higher clock speed and more memory. See Tweakers Page - What video card to use?
Sounds like you might be confusing Preview for Render - they are two different things. You might also be confusing Work Area for Comp Duration - again, two different things.
As others have pointed out, the GPU has little to do with rendering.