If you are working in a 10 bit timeline try switching your rendering from 10-bit to 8-bit, you’ll see a significant reduction in render time.
I just created a 10 second 4 layer sequence with a gaussian blur and a crop on each layer, the render time was 72 seconds on a 3.2GHz Octo-core with 8 GB of ram, the same sequence with 8bit rendering took 21 seconds.
I usually work in this mode until I get final approval on a project, then render it out in the 10-bit mode.
Bob Auiler | bob.auiler@mvpcollaborative.com