Im just trying to learn things about pcsx2 and one of things I'm curious about is why the recording is so harsh on the CPU? I use it all the time for gameplay and get 5fps when recording. It doesn't bug me at all believe it or not. I only use built in recorders because it captures every frame. im very thankfull for that.
Video compression on the fly is a CPU intensive process. This is one area where more cores can be quite helpful though. If you have enough HDD space, you might consider using a faster (but less space efficient) codec like huffyuv or similar.
Fraps creates bad looking videos though, compared to the built-in encoder.
As avih suggested, try a fast and modern encoder like x264 with the fast preset.