Yeah that would be a bummer. I might be lucky that my boards tend to only spit out LIBUSB errors after about 2 days and 6 hours, so I can almost always count on a daily (or once every two days) automatic PC reboot to do the job. Only problem then, is the trouble getting the boards to actually start at 950mV on the first go. Usually doesn't happen... so to avoid stuffing around every 1-2 days, I just leave the boards at 850mV.

On a related note, some power consumption figures if anyone is interested (4x 8-boards):

88.50GH/s @ 130W = 0.681GH/W (all boards at 950mV -- takes many attempts to get started, fails after 2 days 6 hours...)
81.25GH/s @ 105W = 0.774GH/W (one board at 950mV, others at 850mV -- takes many attempts to get started, fails after 2 days 6 hours...)
76.70GH/s @ 95W = 0.807GH/W (all boards at 850mV -- starts reliably, at least a week of uptime, probably more if I just let it run)

The base PC takes up an extra ~30W including fans, so with that included:

88.50GH/s @ 160W = 0.553GH/W
81.25GH/s @ 135W = 0.602GH/W
76.70GH/s @ 125W = 0.614GH/W