Is logic 9.1.8 using all cores? (images included)

So i have a small project with only 11 used tracks, only 1 software instrument. All audio tracks are frozen.

I have an i7 2.8ghz with 16g of ram and logic is getting overloaded.

At standstill in the project (with only activity monitor open) the cpus look like this:

Then when i play the project it looks like this:

Is that normal?