Lag in recording at predictable times

[Xirix]

My friend's recordings when playing steam games have noticable frame dips at fairly predictable intervals, roughly every 2 minutes it'll dip for a few seconds, I don't have his settings with me at the moment but what would be the most likely suspect for this kind of behaviour? HDD throttling?

[AddictivePenguin]

I can think of 2 things, either the Hard Drive throttling as you said which is the must likely thing to happen, or a CPU/GPU overheating problem. Those 2 things can be very predictable and could be causing this problem. I just need to know 1 thing to tell you which of the 2 cases is true here. Do only the recording FPS drop, or do his FPS drop in general? If it's just the recording FPS, then that's the Hard drive, else it's an overheating problem.