Get the latest tech news

%CPU utilization is a lie

I deal with a lot of servers at work, and one thing everyone wants to know about their servers is how close they are to being at max utilization. It should be easy, right? Just pull up top or another system monitor tool, look at network, memory and CPU utilization …

Just pull up top or another system monitor tool, look at network, memory and CPU utilization, and whichever one is the highest tells you how close you are to the limits. And yet, whenever people actually try to project these numbers, they find that CPU utilization doesn't quite increase linearly. To answer this question, I ran a bunch of stress tests and monitored both how much work they did and what the system-reported CPU utilization was, then graphed the results.

Get the Android app