I don't understand the answers in this thread. You will NEVER get the same performance recording with FRAPS (or other) because you're using a lot of resources to "write" your gameplay on disk.
If you were playing games like minecraft or other less demanding games than FRAPS would be perfect for you...but you're not.
You need to get a video capture device that is hooked up to an external storage device (external harddrive). That, won't affect your PC performance because it's operating externally.
This TH post reply is a good one in my opinion.http://www.tomshardware.com/forum/321266-33-video-capture-hardware-gaming
You should do a bit of research for whatever'll be your needs (in video recording).
Hope this helps.