setting affinity CPUs has stopped making a difference to CPU useage

[stayinwonderland]

I'm not sure if it's a vray thing as I recently upgraded but previously, if I wanted to use another program or browse the web during a render, I'd just turn off one of the 8 CPU threads and a struggling web page would immediately jump to life as it would free up some CPU useage.

 

But now, even with two threads turned off for 3ds max, it says 100% CPU usage, and a single web page will struggle to even load a CSS file or image.