Understanding load average vs. cpu usage

linux operating-system load
Niet the Dark Absol picture Niet the Dark Absol · Feb 7, 2014 · Viewed 83.3k times · Source

Okay, I'm very much a Windows user myself, so my knowledge of Linux-y type things is a bit limited.

However it was my general understanding that "Load Average" is an indication of how many processed are being run at any given time, on average over the last minute, five minutes and... fifteen minutes?

Anyway, I've been monitoring my server because we had a big opening and lots of people!

See?

I've been watching top and noticed something that seemed contrary to what I thought I knew.

If the load average is at 7, with 4 hyper-threaded processors, shouldn't that means that the CPU is working to about 7/8 capacity?

Why, then was it showing 50.0%id? How can it be idle half the time?

Answer

user184968 picture user184968 · Feb 7, 2014

top shows CPU utilization for running processes while load average shows (since 1993) number of running processes plus number of processes in the uninterruptible state. Processes waiting for work do not consume CPU. As a result top CPU utilization is less that 7/8 * 100%.

Source: http://www.brendangregg.com/blog/2017-08-08/linux-load-averages.html

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