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I like the way System Monitor on Ubuntu displays the usage of different cores on the CPU. I write multi-threaded applications and it is useful for me to see how many cores are being occupied, for how long and with how much utilization. All of this information is neatly summarized by the CPU utilization in System Monitor.
Now, the problem is System Monitor itself takes a lot of resources to run. For example, it takes 16-25% of a core when I'm running it.
Is there an alternative to System Monitor that utilizes lesser CPU and has CPU visualization that shows utilization of all individual cores?