You mean 30% of a single frame or 30% of 13 thousand frames. 8 hours for almost 4 thousand frames is really not bad at all. And you will get huge files sizes because virtualdub will output an uncompressed file. Simple math will you get there (num frames * num pixels per frame * num bits per pixel). After effects can definitely export compressed videos (e.g. H264 mp4). I don't know about virtualdub encoding settings.

If you want to render minutes of footage quickly, you're probably looking at the simplest scenes possible, or a render farm (you can find online render farms to upload your files to).

Hope that helps.