I noticed the same thing on a 2.8hz 6 core AMD, 16 Gig's memory, 3 tb's free disk space, and 2 gig video card, win7pro. Compared to my NLE running 3 to 5 times slower (I tried ACHD, QuickTime, and the other Codec). Whats going on? If we do a cut or add a filter does CS6 always recode, No background rendering?
Ok here's what I found. If you use only the layer tools the rendering is as fast as my NLE. However if you make the video clip a smart object and use things like filters/sharpening the rendering time even at the same bit rate and codec type it slows way down. So use the smart object with filters etc knowing that it will take a very long time to render. Still usable for that special effect on a short clip but not for full production as a smart object. This is great for doing some basic editing on lots of files and then doing the stuff in your NLE that CS6 won't render fastly.
Test this on your machine by :
1. bring a clip in and render it to the same bit rate/resolution
2. Do some levels or other layer action and render.
3. bring the same clip in, change to a smart object
4. do the same layers stuff
5. do something like sharpen
6. render - you will see the time difference.
