Sony Vegas Pro 10.0 64bit - Slow Rendering Time with i7

Hey, for some reason my vegas pro is slow when rendering out HD video. I'm using the Mainconcept AVC when rendering and it takes around 7 minutes to render a 1 minute and 20 second 720p 60fps file.

Here are my specs

i7-2600k @ 3.4ghz
16gb ddr3 ram
nvidia gtx 580
2x western digital 1tb black

Shouldn't my rendering times be a lot faster?