Mr_Bojangles

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In task manager, I can see the total percent of my CPU that is being used. My question is, percent of what? Percent of maximum commands that can be performed each cycle? If that's it, why do I experience slow down at percentages less than 100? What happens if im at 100%, and try to push it further? I would appreciate if someone could expand my understanding of the subject
 
It's a metric that should represent 100% of the instructions that the CPU could process at the time of sampling, but it's quite a bit more complex than that. Slowdowns occur because the CPU is waiting on I/O, e.g., waiting for the hard disk to transfer data, waiting for another process to complete, etc. You can't exceed 100% CPU utilization.
 

Mr_Bojangles

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Ah, thank you, what happens when you do get to 100% tho, and send it another command? Do you just need to wait till some processing power frees up until that new command is executed?
 

Yes, but it also depends on process priorities. Higher priority processes are executed before lower priority ones, even if they were started later.
 

someguy7

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It, well the OS divides up the load based on priority. If you're at 100 percent and load another heavy app it will run slow(compared to normal) and the whatever else that was running at 100 percent will then run slower.

Example. Video encode=2 cores at 100 percent.

Video encode+mp3 encoding= 2cores at 100 percent with lets say 70 percent doing the vid encode and the audio is uses the remaining the 30.

 

Mr_Bojangles

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I got that, I was curious why it slows down at lower percentages then 100%, is it possible to design a system that doesn't bottleneck at anything below 100%?