What claim, specifically?
That recording to a dedicated drive helps? That faster sequential write speeds help?
Take a look at some of your videos, and see the bit rates. Recording 1920x1200 at 30 fps, lossless RGB, in a game with detailed textures that can't be compressed much on the fly, results in ~8GB of video per minute of recording. That's more than 130MB/s which is beyond the capabilities of cheap SSDs, and all SATA hard drives, except at the very beginning of the drive. Even at lower bit rate you still need some slack so a momentary disc access from something else doesn't result in a string of skipped frames and stuttering.
What exactly are your goals? You will see a frame rate drop while recording with FRAPS, virtually no matter what kind of system you have. It's a demanding tasking recording and encoding video on the fly at upwards of a gigabit per second. However, it should not be difficult to get smooth gameplay, with only minor adjustments to your hardware.
Originally Posted by WuLF
Also, try using Playclaw. I've bought it, and it's superior to FRAPS in every way. My YT channel can show you quality.
I own PlayClaw as well, and while it does have some nice features and advantages that FRAPS does not, it's most certainly not superior in every way.
FRAPS is very well tuned for the single type of compression it supports and it's lossless RGB recording is visually identical to no compression on PlayClaw while only being about 1/3rd of the size.
PlayClaw is better if you are willing to sacrifice some quality for speed, but FRAPS cannot really be beat at higher quality.Edited by Blameless - 8/15/11 at 12:10pm