When you decide out the desired number of physical cores/threads (see below) you want to use, align the 1's and 0's from right to left starting with cpu-0. If you want cpu-0 active, you place a 1 under it for visual reference. I am running a Core i7-6700K that has 8 threads (4 physical, 4 logical). In that case that would be the following CPU Threads/Cores turned on:

That ends up being 1111 in binary...or 15 in decimal. The CPU Affinity Mask will end up being 15

If I want to use a specific pair or quartet or triplet (etcetera) of cores you can also do that:

The binary result would be 0011...which means the Affinity Mask should be set to 3.

You can even use this to specify which specific cores to use:
0101 = 5

First you need to set all your in app settings to whatever you desire. I maxed out most of mine. Then save the configuration. Note the location where it is saved to.

Open up the CFG file you just made using Notepad and you add the section calleda [JOBSCHEDULER]. It should look like this...but replacing n with a Decimal number representing your calculated CPU Affinity Mask from above.