Good to know that you can do four at these numbers. I was about to adjust all sticks on two Superbpages (8=4 ea).
Four/s-pag are pretty stable: I run four at bfgminer at default and four at cgminer gekko at 200-all ~11GH (have an experimental one at 800mv/350 on Anker with Y-that one could do 425, but require too much of a cooling effort).
I was thinking of trying just three/superbpag on 350 since I have a 2A/slot usb 2.0 Plugable coming tomorrow, so i can relocate two there.
Will report if 3 sticks/S-pag at 350 work or not.
EDIT: why do you think that four sticks consumed more than 70W even at 340? That would be 17.5W/stick for only ~17-19Gh/s or so. Seems excessive.
I've run 4@400 on the Spag - the hub gets rather warm but not uncomfortable physically (mentally that's another issue) and of course the heatsinks are hot but not burning with two usb fans from the 2.0 hub. I'd think you can run 2x4@400 on 2 Spags so long as they're not stacked and have room for air..
When Run 2 comes in, and 812 is repaired, i'll be doing just that...
Now, as for 8@425.... cooling would DEFINITELY be an issue!