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How can "%" of CPU be more than 100?
- Thread starter Richard1028
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Each cpu core is up to 100%. So with a dual core machine you get up to 200%. My MacPro gets up to 800%...
correct. its confusing, and its not like a core is its own processor; thus making things really weird.
Ah, got it. But wouldn't it make more sense for activity monitor just to divide by "2" on a dual core (since precent implies a limit of 100?)
Maybe - but if you go over 100% then you can see that the app is multithreading and using multiple CPUs.
Given that most computer CPUs these days are a similar speed (2 to 3GHz) and more power usually comes from having ore CPUs, the % rating is also quite a good measure of relative speed.
There's probably some marketing in here too...
Either way is good..
One thing I like about this way is if a process is unresponsive in OSX, Activity Monitor shows it using 100% CPU and so is readily identifiable. On Windows, it's at 25% (on a quad core machine) or 12.5% (on an octo core) so it's not as obvious.
Since many processes execute only on one core/processor, I think it makes sense to specify that process' CPU usage just in terms of that core.
Actually it basically is. A two processor machine and a two core machine are identical for virtually all uses. The only real differences one could measure are in bus/cache contention.