Denver Root
Jul 27, 2017 · 1 min read

Keep in mind that the activity monitor on OS X and Mac OS shows you CPU usage percentages per core. Meaning that if it shows a particular process is using 15%, that means it is using 15% of one core of your CPU, not 15% of your total CPU. Also, as modern CPUs typically all support hyper-threading, each core is virtually represented as two cores; so, in reality, on modern computers, the activity monitor’s CPU percentage is actually showing you the percentage of CPU utilization for that process on one-half of one core.

Bottom line: In order to determine the actual CPU utilization for a process on Apple’s PC operating system, you need to divide the numbers showing in the CPU utilization column by the number of cores your CPU has, and if your CPU supports hyper-threading, divide that again by 2. Although this certainly does not change the overall point that you’re making, because you’re totally correct in the fact that Slack’s resource utilization increases quite a bit for each new team, it’s not actually using near as much CPU as it might first appear. Apparently Apple thinks everyone who knows how to open the activity monitor also majored in math. 😜

Denver Root

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