What is causing stutter in my recording?

[Sampsy]

When recording games using afterburner uncompressed (looks far better than compressed) at full frame (1080p), 30fps the video being recorded is filled with stuttering, sometimes with the audio skipping. The game while recording does begin to stutter a bit, but not nearly as much as in the output video. Frame rates do drop a bit, but are well above 60fps.

I am running a 2500k @ 4.8 and a GTX 670. The problem occours when recording onto my OS drive (Agility 3), data drive (Samsung Spinpoint f3, with the game running off it) and an external hard drive (probably not the world best, and connected via USB).

Is the issue being caused by the hard drive's ability to write the data quickly enough, or is something else possibly causing it? Clearly it would be a waste for me to buy a new hard drive to record video onto for it to not fix the problem.

Note: Fraps has the same problem as aterburner.

 

[RomanNose]

Have a look at your disk io when running, see what it gets to.

 

[Sampsy]

How do I do that exactly?

Edit: Looking at the resource manager I see the I/O fluctuating wildly, the highest I saw it reach was 104MB/s although I can only see it with the game minamised. I see the video taking up most B/s with the most I saw at 70mb. This seems to be the sum of a huge number of other images in C:\System Volume Information\{code}. Is this an attempt at the o/s to store pieces of the video in temporary memory to be written into the video file at a later date as the hard drive can't keep up with it? It seems to me this might be the case. Minamising the game while recording pauses the video capture, however it takes a while (depending on how long it was recording with the game in focus for) for the disk activity to fall.