Computing Walk Forwards doesn't use any resources whatsoever: Disk no activity, CPU 1% - how is this possible?

When running a WF Matrix test, the optimizations part of the run consumes 100% of the processor resources, it then switches to computing the various WF runs. In my case each run takes around 10 minutes. But during the entire time the processor never goes above 1%, the disk drive is not being used, memory allocation is not changing -  in essence during these 10 minutes no resource of the computer are being used whatsoever...yet it spends 10 minutes computing the WF run - granted, it completes the task after 10 minutes, but what is it doing during these 10 minutes if it is not consuming any computer resources? I cannot figure it out, surely if it is computing something it should be using the CPU - and all of it? 

I posted something similar here, and while it feels a little better, the complete none use of computer resources and CPU - still the case now in 118 - is confusing the whats-it out of me?! 


How or what is it doing it?!


https://roadmap.strategyquant.com/tasks/sq4_4024