One item of note: The numbers that Phillip comes up with I assume are measured "at the USB connector" as I understand it. The actual final "at the wall" efficiency won't look as good, since there has to be power supply, and hub losses. These numbers also, except for some early ones, don't include the PC that's running the mining software.
When compared to an S5 for example, where it's all pretty much bundled together, you only really get to measure the "at the wall" figure. That's I think where the .52W/GH comes from .
Don't get me wrong, this is all really good work. It's just not quite as good as it seems is all.
A lot depends on how you set a stick up.
my pc is really efficient . it runs a node at 25 watts and if I choose to run 1 stick at freq 125 . I won't need a hub or a fan.
if sidehack makes a usb hub that allows a psu to power it the hub would be very efficient .
the s-5 is 1150gh and at .52 per gh you get 598 watts.
the controller and the 2 fans are close to 20 watts of waste so 578/1150 = 0.502 watts a gh.
your argument is valid if the pc/rasp pi/cubie/bugle bone were never going to run. that means all power used by the controller/fans/hubs counts against the watts per gh.
my 1 stick 1 hub 1 fan is pulling more then 8 watts to do 11 gh. i do not count the 25 watts for the pc since i was using the same 25 watts to run
the node.
now if I add 2 more sticks and go to 16 watts to do 33gh I am at 16/33 = .4848 watts per gh not counting the pc's 25 watts.
buts a guy with a rasp pi will use 16 + 10 = 26 watts for 3 sticks a fan a hub a rasp pi this is 26/33 or 0.7878 watts a gh
many people don't want big home mining. 26 watts vs 600 watts almost no noise vs lots of noise.
for sticks to really beat an s-5
10 at 11 gh = 110gh watts per gh at .33 = 36.3 watts + 10 watts for rasp pi = 46.3 watts add 3.7 watts for fan and hub waste you are doing
50 watts to get 110gh that is 0.4545 watts a gh and beats the s-5 in power use and sound use. so the sticks show under clocked chips work well.
carry forward to an 18 chip board and maybe we have a special piece of gear.
210 gh at 75 watts using a hub and a rasp pi will bitch slap the s-5's .52 watts a gh.