According to the Rough Guide to MBus Modules it's only a 90MHz SuperSparc II. I haven't played with 'em in so long I don't recall if they're really 95MHz or not. Re: heat and the SS20 -- yeah, I started pulling DIMMs out of it on a hunch. ;^) Still wedged, and I wandered off to some other project. Oh yes they are. I mean not compared to a 19" rack, but this thing is huge for a non-rolling box and has to be over 80 pounds. I didn't realize what a pain it was going to be, and am wondering where to put it... The middle of the living room really isn't the best spot. I'm also looking forward to this huge machine running off of a tiny little lunch box (Sun 411) for storage... --Steve.