Yeah, my PC doesn't struggle with Mach 3 either. Where I'm told the "just barely works" part is windows it's self. I'f had a couple failures with it just by pushing the Tab button to get rid of the jog window. It's also stopped on me one other time when I bumped the keyboard. I'm not complaining, just like to have it running the best it can.
My friend says anything will run under Linux, that's the point of Linux... you just have to have Linux set up correctly. I'm just asking around to see if anybody has jumped in to it. Maybe I can get him to! If so, I'll definitly post it here.
Thanks!
Chris