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On a multicore machine, does the JVisualVM CPU usage graph show total machine CPU capacity or something else?

As an example, on a machine with 16 cores, if I see CPU usage in JVisualVM going up to 50 percent, does that mean the equivalent of 8 cores fully in use?

Rich
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1 Answers1

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I just tested with VisualVM 1.3.2 and the CPU display is calibrated so that 100% is 100% of all cores.

I tested by creating a simple application that entered a tight while loop upon launch. I verified using Activity Monitor that Java was using 100% of one core. In VisualVM it showed approximately 12% CPU usage.

Ben Baron
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    Thanks for going to the trouble to provide an answer! – Rich Feb 08 '12 at 07:28
  • No problem. I was actually looking for the answer myself and stumbled on your question. Since I couldn't seem to find the information anywhere, I decided to just go ahead and test myself. Hopefully this will be helpful for others in the future. – Ben Baron Feb 08 '12 at 20:19