A very good suggestion. Yes, of course, the AffinityMask could go higher than 255 (I should have known better, since I've own a 16-core Mac...), but if it was still made as a slider, going up to even 16 bit ( 65535 max ), would be very cumbersome to use.
So, your remark gave me enough motivation to change the interface for tweaks to allow other kind of controls other than the slider so I managed to add what I always wanted to add, a proper AffinityMask tweaker, intuitive to use without having to figure out binary arithmetic.
If you reinstall GSX or the Addon Manager now, you'll get the updated Addon Manager from the online server, which has the new user interface for the AffinityMask. It goes up to 16 bit, it should be enough until CPUs with more than 8 (real, 16 with HT) cores will be released.
Note that, there are two rows, the topmost shows CPUs with even numbers (2, 4, 6, 8, etc.) the lowest one shows the odd ones (1, 3, 5, 7, etc.), so the top row indicates your real cores, the bottom row indicates the Hyperthreading virtual cores, so I guess it should be simpler to get a better idea of what you are doing when assigning the Affinity.
