Use Gspot to find that. Export a timeline with AME and run it through Gspot. But what is the relevancy? Why?
I can play back AVCHD smoothly with <50% CPU. However, editing in Premiere is quite slow.
Your video card is not going to help in that respect. You need:
1. LOTS of CPU power
2. LOTS of memory
3. GOOD disk setup
9. DECENT video card.