First of all many props and thanks to Canary!
I'm running 1 cube and 2 blades ( 1 oc to 13 ) off a HX850.
I love these power supply's, got 2 more that have been on 24/7 over 8 months now pulling 750 watts continuous.
And a $350 electric bill to go along with it.

wow!! your rate must be insanely high to pay that much for less than 750 watts continuous... holy cow!!
-edit I'm not complaining about my bill then...
That's 750 each x 3 + 2 600 watt Thermatakes @ .13 cents a Kwh
That long at 90% load is impressive to me. These thermaltake's have surprised me, they have ran over a year and a half at 450 watts continuous each.
Those receiving cubes should take apart your cube and reassemble it carefully making sure all the screws are tight and the boards all line up within the grooves inside the cube.
I initially ran slush's proxy on a GPU mining rig but it only let half or less of the cube hash, I had lots of chips sit at 000. Moved proxy to another PC on same switch it works fine.