I recently purchased an '09 Mac Pro 2.66 quad core with a Radeon 5770 and 12 GB of RAM. It's a pretty powerful machine for my needs but I'd like to squeeze a little more oomph out of it for 3D gaming and some video editing. Given a limited budget, would I get more bang for my buck with a CPU upgrade or should I look into a better video card? I've seen the cpu upgrade videos for this machine and this seems like an upgrade I could definitely handle. What processor or video card would be a solid upgrade without breaking the bank?