After some researching...I don't understand why this "works" in INS at all. ESPECIALLY since the command for it in other games is only "0" and "1", not dependent on how many cores you have.
This command was fully implemented with the orange box engine...you can type mat_que... into the console of orange box games and it'll pop up..but not insurgency. Insurgency is running on a build of the source engine from 2004. In orange box games I have used this one, I get around 10% FPS boost..not insurgency. I think "results" garnered from this in the current release of INS are unrelated - or it's some sloppy half-implementation that is there for some reason.