I've got an HT computer running 2 instances simultaneously, and i'm thinking of using another instance when one of my instances has finished folding, but I don't want to connect up to the net just to upload the data (I'm on dialup, and dialing up 2-3 times a day gets costly).
Does having 3 instances (but only 2 running at any given time) muck up the configerations of any of the instances? They're all in separate directories, with different machine IDs.
This should work fine (as long as you're using the -local flag), though it seems like an awful big hassle just to get an extra 15% performance out of your machine while you're waiting to dial up. Personally, I would just try to make sure I have at least one instance running. The difference between one instance and two on a HT machine I beleive is only about 15%.
Also, keep in mind that work units have deadlines. You don't want to hold on to a unit too long before you start processing it. This would also negatively affect your performance fraction, which could lead to you getting assigned undesirable work units (or not, I'm not entirely sure what criteria the assignment servers use).
Also whilst I'm here, can I confirm that if I install FAH on another person's computer, using my username, their machine ID must be unique, relative to what I've got already?
Machine ID's only have to be unique for multiple instances running on the same machine. So if you run on somebody else's machine you're free to use any ID you want (just make sure every instance on that machine has a unique ID).