Post
Topic
Board CPU/GPU Bitcoin mining hardware
Re: Mhash/Watt for Complete Systems
by
DeathAndTaxes
on 02/02/2012, 18:59:23 UTC
2.72 MH/W 2300 MH/S @ 845W (at the wall, dedicated 240V circuit).
2.65 MH/W 2300 MH/S @ 870W (same system on 120V circuit)


5x7970
filesys:    wd green 500g  win7  diablo
voltage:  1.056
clocks:   1049/685
killwatt:  1160
Mh:        3120

2.69 MH/W



Dat.  how did you measure this on the 240v, i have my 79xx on 220 now, but cannot measure the watts directly

TADA ....



Well I measured amps & volts.  Remember the two legs of 240V circuit in US wiring are out of phase so to read current you need to clamp just one conductor. 

They make adapters like this:
http://www.service.kleintools.com/Marketing/Catalog_Imagery/69400_ICON.JPG

but I have the rigs connected to a PDU using C14 to C13 cables and I doubt anyone makes an adapter so I modified one power cable which I use for testing only.