I am rendering for the first time with my i7 2600k overclocked @ 4.3Ghz.
It is currently rendering a 1.05GB 1280x720 60fps GoPro .mp4 video, with 2 slight colour correction and vignette effects added.
It is taking around 20 minutes to render 10 minutes of this footage. This seems pretty slow to me, considering all the hype I have heard about this cpu. It is rendering in Sony Vegas, and also has GPU support enabled. I have a GTX 560 ti 448 @ 880mhz.
CPUs aren't great to render with. GPUs work much better, and better still is QuickSync, which is a bit of fixed function logic found on Sandy Bridge and Ivy Bridge CPUs. It's pretty much the fastest thing around and doesn't max out your CPU's cores to do it (since its functions aren't part of the normal CPU logic).