I ran a Java applet, and it used over 200% of my CPU....

%CPU 273.5

It actually rose to over 400% after I took the screenshot.

How is this possible? Can someone explain why Activity Monitor shows a task as using more than 100% of my CPU?


The CPU percentages shown in Activity Monitor are 100% for each virtual core. If you have a quad core processor with hyperthreading, 'real' 100% is 800% in Activity Monitor.

  • Is this because of hyper threading that each core gains up to 200% per core? – Ben Sinclair Jan 23 '18 at 13:12

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