Does file size affect render speed in Sony Vegas? This is probably a dumb question but bear with me. If my raw video file size is smaller, will that speed up rendering time? Let's say I have a 500 mb video clip, and one that is 250 mb, but the same length. Will the 250 mb one render faster on the same settings?
It depends of codec/frame size in these files.

H.265 will render slower then H.264
FullHD will render slower then SD

More information about source files needed.