Since recently I have a strange performance problem in Windows 7 64-bit.
I am programming a JUCE stand-alone application. My audio calculations are quite CPU heavy. So it can happen, that I get drop-outs, because I cannot fill the audio buffer in time (typical stuttering sound as the result).
The strange thing is: The dropouts are actually affecting my whole Windows system. As soon as dropouts occur (even mild dropouts) Windows completeley freezes. Everything runs in snail-pace, clicking on the Windows Start menu has a lag of several seconds, etc. The audio sounds still fine though. Apart from dropouts once or twice a second.
I am pretty sure: it was not like that before. Before Windows did not freeze, when dropouts occured.
I want to add: my audio calculations use only one core. But I have a quad core CPU. So even if my audio calculations take all the CPU on the core, it should not affect the other three cores. And Windows should be able to run normally.
Or maybe that assumption is wrong? Can an audio thread running on one core, stall all other cores?
The thing is: when my application runs fine (no dropouts, Windows is responsive), the Windows Task manager tells me, that my application is using about 21% of my available quad-core CPU.
But if I slightly increase the audio load, the problem starts. In the Windows Task Manager I can then see, that all four cores suddenly jump to a load close to 100%. Yet the Task Manager still tells me, that my application is only using about 23% of the CPU time. I am confused.
Any idea, what could be the reason?
Has anyone experienced something similar?
PS: Yes, I already tried to turn it off and on again. Still the same problem