Easy undervolting guide for 79xx and R9 280X cards

hi all, I just registered to say a big thank you to the original poster for the guide. I am new with mining and bought a gigabyte r9 270 (no x) and i am doing vertcoins mining. I wasnt able to undervolt it using afterburn, when yesterday night I found this guide by google and now my card is running at a max of 1.163.
What if I would to undervolt even more? Should I type in the last power state the voltage I see in the third state (starting from bottom)?

How many Watts do you think I am pulling from the wall now with only my video card? It is running 1050/1500.

ps. my asic quality is 72,9 %. is it good or bad?

Update: I was able to stablize my 7850's at 1.200v. That's only a 0.019v drop, but considering the sizable overclock that's about right. The plus side is my temps are about 3c lower from such a small voltage drop.

Thought I would necropost this back to the top.

Got my first HD7950, a Gigabyte, from a forum member in trade for a PSU a week ago or so. It was running the Stilt BIOS at 1.09V. However, any time I ran scrypt or anything else demanding on it, it would heat up, pass 87 degrees, and throttle out. It did this no matter where in the main rig I had it.

So, I went on a quest to see how low it would go and still do 1100 MHz engine core. Tried 1.075... took longer to throttle, but still did it. Went to 1.05V... brought it to 86 degrees but didn't seem like it wanted to throttle anymore.

As of today, I'm at 1.02V. 84-85 degrees, no throttling. I don't like that it still runs this hot, but at least I can actually use it now. X11 and X13 now have this card in the low 60s... at 1.09V it was still doing mid 70s.

So, I figured I'd let you all know that for at least this card, 1.09V still is a long way from the most optimal voltage. Haven't had a problem yet at 1.02. Tempted to push my luck even further, but I think my next move is to see about re-applying the thermal grease. It's got a 140mm fan blowing fresh room temperature air right on it - I can't believe it's still running this hot.

Tried replacing the TIM?

Not yet - I don't have any. As mentioned, that's probably the next step when I can afford to get some more. Scoured the house, and all the TIM I had is gone.

Meanwhile, I figure X11 and X13 are this card's best friends until I can get some.

Edit - went digging through a box and actually found some TIM... a nearly empty vial from an old CPU heatsink. Pulled the cooler off the Gigabyte, and there was almost no TIM left on the actual core - it had all run out and clumped up on the side. Yikes!!!

The card is now running ten degrees cooler on scrypt - 75 degrees.

thank you very much for the guide.

stock:
1.256v
1020MHz Core
1500MHz Memory

78°C max. in Unigine Heaven Benchmark (Extreme)

down to

undervolted:
1.150v
1020MHz Core
1500MHz Memory

61°C max. in Unigine Heaven Benchmark (Extreme)


17°C less than before. that's awesome if you ask me.

Anuran said:

thank you very much for the guide.

stock:
1.256v
1020MHz Core
1500MHz Memory

78°C max. in Unigine Heaven Benchmark (Extreme)

down to

undervolted:
1.150v
1020MHz Core
1500MHz Memory

61°C max. in Unigine Heaven Benchmark (Extreme)


17°C less than before. that's awesome if you ask me.

Click to expand...

1.19 or so volts will get you up to 1150Mhz core clock and keep the 1500Mhz memory
A little extra boost for those demanding games.

yop. im at 1119mV(MSI Afterburner) although i've set VDDC to 1118 in VBE7. maybe just rounded up?!

another 2°C less. 59°C in Unigine Heaven Benchmark (Extreme)

i can start increasing the core clock now i believe

Found out the hard way that the vbe7 method does not work on my MSI Twin Frozr 280X v38SB due to BIOS variations. You can mod them but Windows will boot to a black screen.

Instead, mine is running a custom BIOS modded by kqpahv here at 956mV. Runs stable at 1040/1500 for mining, but I have not yet seen whether it's stable for gaming at those settings.

Runs ridiculously efficiently now. Mining XMR in auto fan, the fans only go to 35% with temps at 73 degrees. I want more of these cards now.

since i saw your post with 1040/1500 @ 956mV, i gave it a try too..

1020/1500 @ 1000mV and crash. a bit disappointing. another try..

1020/1500 @ 1050mV and guess what? crash again

the least i can go is 1020/1500 @ 1100mV. well, it cant be helped.

I was honestly surprised my card was able to do it... thought I would have to flash the original BIOS back on, and that would be the end of that.

i try to convince myself that my 280X is made for overclocking. wish me luck haha