I am trying to stealth The Ballade Of Blocks with Fraps running in the background. Normally with the stealth videos I have recording the run is not an issue. However, with this intense song even the slightest micro-stutter will cost me the stealth (it has happened a few times and it pissed me off

). Unless I can make the stutters go away, it is impossible for me to get a recording of a stealth on the Ballade Of Blocks.
What I tried so far:
1 ) Disabled Avast anti-virus (no effect)
2 ) Decreased resolution so I could get better frames/sec (improved but there are still occasional stutters)
3 ) Ran AS on 1 CPU core and Fraps on the other CPU core (actually ran worse like this)
What else can I try?