I was looking into this, using the "Nice" cmd variables but I couldn't launch from console with a priority -10 even with sudo something along the lines of ".wine does not belong to you" came up. So I tried to manually change it inside the system monitoring GUI where I was able to set a -10 priority on HL2.exe. (in this case GMod) But it still seemed to run choppy-ish, however I think I need a more permanent kind of setting instead of just going that way.
