Reply to MPB 2011, Live 8 open, slow computer. Is this normal ?

So whenever I have a Live 8 project open and I decide to take a break from it and browse the internet a bit, it's really slow. Is this normal ?

I just have like 4 tabs in Chrome open and itunes. And Live 8 of course.

Especially Chrome is painstakingly slow sometimes.

I also checked and I seem to be using 2-3 GB of 4 GB of RAM, that's probably it right ?