Comment by dijit

It's possible, the kernel itself not using more than 8 cores will be imperceptible except on things like network devices where theres' no userland<->kernel barrier. In those kinds of high-throughput applications usually you offload things the kernel does to hardware anyway.

You'll lose your mind once you realise that Windows NT handles a lot of things single-threaded. I had a situation once where I was handling a few million packets per second of TCP on Windows and it only pins a single core.

Though: that's not what TFA is looking at: in this case you're not actually limited to 8 cores, you're limited to slicing your executions into 8 parts per cpu per "tick".

This is a known way of scheduling, you only get 1/8th of a tick with a fair scheduler.