Why do the CPU stats vary with ps and top?

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The commands ps and top express CPU time differently. While ps calculates it by "total CPU time" divided by "time task is running", top shows the value as a percentage of overall CPU time.

For ps, this means that the longer a process is running without a high CPU utilization the smaller the value of %cpu gets (it converges...

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Why do the CPU stats vary with ps and top?

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