undefined | Better HN

0 pointsScramblejams6y ago0 comments

We can't compare about CPU values

Can you explain more why we can't compare? Looking at this chart...

https://stressgrid.com/blog/benchmarking_go_vs_node_vs_elixi...

...shows pretty clearly how the CPU utilization grows linearly (ignoring some sawtooth) as the load increases, plateaus once the load remains constant, and then comes down linearly as the load decreases on the other end. Looks like a very clear mapping between work done and CPU load to me.

0 comments

1 comments · 1 top-level

Zingler6y ago

It is explained in the blog post after that benchmark - https://stressgrid.com/blog/beam_cpu_usage/ .

Essentially in order to optimise responsiveness the BEAM uses busy waiting, which in reality is not actually utilising the CPU as much as is reported by the OS, which results in misleading CPU usage being reported by the operating system.

j / k navigate · click thread line to collapse