Need DPC (Deffered Procedure Call) experts!

Hello, I have little to no experience when it comes to DPC, but I've been having this problem with my laptop this month which seems to have arrive "out of the blue".

I noticed it this week when I got completely random FPS drops whilst playing Left4Dead, so I looked at the Task Manager and realized that every short fps drop correlated with l4d's cpu usage dropping for a 1-2sec, but nothing was using that.

I booted up Process Explorer from sysinternals and found out that every drop correlated with DPC using a large amount of cpu then dorpping back to 0.

To sum it up it seems that because L4D uses nearly 100% cpu on both cores, it gets a stutter when DPC "steals" from it.

I did research on DPC and used the Windows Performance Analyzer tools (xperf) to log what's using and here are the results:

After playing L4D for a little bit to log these incidents, here's the table for DPC Usage:


...and the graph:


I can upload the log if needed. Was made with a xperf.exe -on DiagEasy


I thought maybe there is a problem with some USB appliances so I unplugged them all and that usage went away, but I still got stutters ingame. Any ideas/opinions?

 

Is this in the wrong forum?

 

No one around with DPC experience?

 

Just closing the issue, there appears to be a problem with my fan, at least, my CPU is overheating when playing a game. Since it is a laptop, it auto clocks down when it gets too hot, reaching 90C. The action of auto clocking down/up every 3 seconds or so because of the changing temperature was my main problem.