Why does running FRAPS video capture slow down game so much?

[PeeluckyDuckee]

I have the 2011 iMac and trying to do video captures at default FRAP settings in NFS:HP and MOH but can't seem to do it without my frames getting reduced to single digits and turning into a slide show. What gives? Is this a HD or CPU issue? The HD is not writing fast enough or gaming while video capture is too CPU intensive? I only have 4GB ram if that makes any difference. Thanks.

 

[nerp]

Fraps is just demanding.