I helped icedrill get his up and running and fixed a few obvious cgminer bugs that only showed up with real hardware especially when it misbehaved (the changes went into git master). He had a 3 module unit. One module was completely dead and had to be disconnected or it wouldn't fire up. One module would overheat and trip the code that disables it almost immediately unless it was run at 20% speed. The final module ran stable at ~420GH. There's only so much debugging I can do remotely on the code without the hardware myself, but there are still bugs in the code preventing it running stable for more than a few hours at a time, but that does appear to be software related. The one working module appears to work quite well at that speed. I know there were a couple of board revisions and I suspect there may have been one more (revision) in the works but not really sure which boards went to icedrill.

I doubt very much these early engineering samples hand assembled are a sign of what the final product will be like, but perhaps that last module is a better indicator. I don't know anything about his power consumption.