The "-1" just tells the game to leave CPU multi-tasking decisions up to the Windows OS. The numbers would let you specify a CPU core if you wanted to manage it yourself. So CPUAffinity0=-1 tells the first loaded EQ session to let Windows decide. CPUAffinity1=-1 would signal the same decision to the 2nd EQ session you decided to load. etc., etc. up the limits of your hardware.
