A friend of mine made a 3 min video in Premiere CS4 and added some color corrections using Magic Bullet Looks, and when she try to export MPEG-2 with Media Encoder, the processor use in task manager is about 15 %, and RAM about 2 GB, after some time it goes to 50 % but soon drop to 1-2%
The rendering time for 3 min video is about 2:30 hrs, and it even fails sometimes.
Why is it using CPU only 15% ?
The CPU is i7 920 @ 2.66 (NO overclocking), 6GB RAM, and WinXP 32-bit