If you do decide to get a new processor Definitely Intel, i5/i7. If you plan on a lot more heavy editing or plan to later go for the i7 (preferably 3rd gen since it has quick sync)
After you figure out what's slowing down fraps (be hdd or other) if you still want to try other recording software get the trial version of each and see what you like and what works for you..
List:
Mirillis Action! (This is what I use)
Dxtory
Bandicam
MSI Afterburner
(Obviously didn't include fraps since you have it)
Lesser known.. Playclaw and xfire, but they lag fairly bad from what I see/hear...