I own a Gigabyte 280x with BIOS F31 and according to GPU-Z the voltage at 1100MHz is 1.31V.
What are the voltages with F3 and F12 BIOSes which probably are newer silicon too...F31 must be for older 7970GE siliicon.
I just started playing with undervolting these cards and the first two that I dropped the voltage from 1.2v down to 1.1v dropped a full 100 watt of power from the wall EACH while mining. I was pulling a steady kw from the wall on this rig and now with just those two cards dropped .1v I was able to toss an extra card in.
Anyone know if the R9 280Xs are voltage locked? I'm looking to buy one and want to get the card I can OC the most, so if there are some floating around that aren't locked, I'd like to know about them. Thanks!
I manually set CPU voltage to 1.1000 V in BIOS (Advanced Screen > CPU Configuration > Multiplier/Voltage Change > CPU Voltage). After reboot I see in BIOS (Vcore in H/W Monitor screen) that it is lower: 1.064 V. But Vcore in sensors in Linux is 1.12 without load and 1.13 after some time of 100% CPU load (dd if=/dev/urandom of=/dev/null).