tl;dr: Plug your power supply cables directly into KnC modules to increase system efficiency.
Folks,
I was poking around the inside of a Saturn->Jupiter miner, measuring the 12V supply on the modules themselves.
With a supply voltage of 11.93V at the PSU, I was seeing 11.5V at the modules!
Examining things further, I noticed that the nice quality blue PCIe extension cables KnC supplied are only 20AWG (0.52mm^2).
This plus the resistance at the couplings is wasting a significant amount of power:
Module Power ~150W @ 11.5V = 13.04A (20AWG has rated ampacity of 11A in free air, btw)
Vcable=0.43V
Power loss in cable = 13.04A * 0.43V = ~5.6W
Plugging the PSU cables directly into the modules I measured around 11.85V. So:
150W 11.85V = 12.66A
Vcable = 0.08V
Power loss in cable = 12.66A * 0.08V = ~1.0W.
So we have a percentage loss of:
100 * 5.6W (150W + 5.6W) = 3.6% versus
100 * 1.0W (150W + 1.0W) = 0.6%
When you consider how much a 3% increase in efficiency costs at the PSU level, the recommended course of action is obvious
E
*Thank you for this post. - confirming what some of us suspected... and removed those long ago.... but certainly still noteworthy to noobs & people who missed it...
Power counts significantly.
on a "related" matter... I noticed that my 65-75 temp range may not be the "Sweet-spot"..and I'm NOT suggesting anyone do this, but I noticed (using Bertmod) the output on the vrm's increases by a noticable rate... from 45-47amps to 50 plus amps OUTPUT per vrm when pushed to 80C.... So I'm testing them all at the moment...
Has anyone had the same result? I'm still waiting for pool results...
