Bitcoin Forum

For the ZEC mining, my R9 390 can do 900MHz at 1.0V. The power draw is about 150W from the wall.

I wonder if someone can measure the power draw of a dingle R9 290, 290x, 390,390x  while running at 947/1250 @1.040mV while mining Zec and Eth(vs power draw at stock voltages and clocks, as 290x/290/390)

I have a pc with 390 and 295x2 on it, 850w gold psu. 947/1250 @1.04 mining zec is 640w at the wall, after completely removing 295x2 240w from the wall so 295x2 with those settings pulls about 400w.

With default settings 860w at the wall  :o

Hawaii doesn't need 1.04V for 947, most efficient settings are normally volts below 1.0 and then find that highest stable core. Zec and xmr need some bios modding but eth is not memory limited so not much to do there.

Strix 390 normally has quite high default voltage so AB -100mV is still too high. Trixx can do -200mV.

you say the 390 uses 240w undervolted-underclocked before or after substracting the idle power usage

240w is that whole computer. I will post numbers without 390 later.

edit: Ok, had to do it hard way.

With integrated gpu only system idles at 40w.
Add 390 947/1250 1.04 zec and system pulls 240w from the wall so 390 adds 200w.

Usually I test with separate psu which powers only the riser and pcie connectors of that gpu, that way you don't have to guess how much gpu uses when idling.

i wonder how low is the power draw when a 290/x or 390/x is giving same hashrate as 300H/s Zec or 28.5Mhs eth?

With that 1.04V average 390 does ~1050/1625 (strapmod) which brings it to 400+ on equihash. I will try how much it needs to be underclocked to do only 300.

Last summer hawaii's were doing 26-27MH eth with 160-180w, must say all this open data to mod straps wasn't available back then.

edit: to do only 300 on zec you need to go really low. Needs more testing, max 120w.

s it measured off the wall? because 120w seems really low