Sharing kh/w on Gigabyte 7970 and R9 280x

ChekaZ

[size=14pt][b]Hey lovely Feathercoinminers,[/b][/size]

Iam going to share my research about the kh/W results on the [b]Gigabyte 7970[/b] and [b]Gigabyte R9 280x.[/b]

First of all I have to say that you need to flash the bios of your cards to undervolt them. I’ve managed to brake the bios of the 7970 that I can regulate the voltage manually while the computer is running.
But on the R9 280x I didnt manage to do that, so everytime I wanna switch the voltage I have to flash the bios for the card again with new voltage stats.

[b]FLASH THIS CARDS ON YOUR OWN RISK![/b]

[size=14pt][u][b]7970:[/b][/u][/size]

I did a lot of research on this one. The following config is based on a single GPU running lonley.

Short explanation: vddc = voltage, core = CPU-Clock, mem = MemoryClockFrequenz

[b]First config -> 722kh/s at 314W [/b]

vddc: 1.075 core: 1025 mem: 1250 ThreadCurrency: 8192 g: 2 worksize: 256 Intensity: 13

cgminer --scrypt -o [url=http://127.0.0.1:8332]http://127.0.0.1:8332[/url] -u xx -p xx -I 13 -g 2 -w 256 -I 13 --gpu-engine 1025 --gpu-memclock 1250 --gpu-powertune -20 --thread-concurrency 8192 --gpu-vddc 1.075

Thats 2.2993630kh/w.

[b]Next config -> 690kh/s at 282W[/b]

vddc: 1.050 core: 975 mem: 1250 ThreadCurrency: 8192 g: 2 worksize: 256 Intensity: 13

[u]CGminer command line:[/u]
cgminer --scrypt -o [url=http://127.0.0.1:8332]http://127.0.0.1:8332[/url] -u xx -p xx -I 13 -g 2 -w 256 -I 13 --gpu-engine 975 --gpu-memclock 1250 --gpu-powertune -20 --thread-concurrency 8192 --gpu-vddc 1.050

Thats 2.446808kh/w.

That are the 2 best configs I could get, The Watt/hour could vary a little bit downwards, cause Iam not using PSU GOLD on this testing cards.

Iam using the 722kh/s config right now, cause I like the extra kh, but if you prefere saving some power, go for the second, its more costeffective.

[size=14pt][u][b]R9 280x:[/b][/u][/size]

I’ve got one really great config right now for them. This config is dedicated to [b]@dLight26[/b] he gave it to me and it worked really fine!

[b]Config: 712kh/s at

aatje92

Hmm, my xfx 7970 uses less power (290w for whole system) with 730kh/s and engine 1061 mem 1760 v 1.075, rest of the settings are the same so i guess theres something to XFX cards?

ChekaZ

[quote name=“aatje92” post=“47686” timestamp=“1388084082”]
Hmm, my xfx 7970 uses less power (290w for whole system) with 730kh/s and engine 1061 mem 1760 v 1.075, rest of the settings are the same so i guess theres something to XFX cards?
[/quote]

@which temp?

aatje92

~45c but it’s watercooled

ChekaZ

bump

If anyone neeeds to safe power/got any questions about flashing/setup feel free to ask :)

Ignition75

It’s 7:33am in Australia and I’ve once again, spent the whole night being schooled by the gods of Crypto Mining.

I’m trying to build a prototype 6 card rig before I put in a big order. I couldn’t get a 6 PCIe slot MSI Mobo to read any of my Sapphire 280x cards. Such a journey I’ve been on, I tried everything, different operating systems, shorting the PCIe slot, making dummy plugs, prayed to 4 different gods…

Guess what it ended up being?

The Mobo didn’t like recognising the cards for the first time because they were undervolted to 1.075… As soon as I took them back to normal voltages they all worked on the new Mobo and [b]THEN[/b] it allowed me to undervolt them happily…

I wanted to pick up my prototype rig and smash it to pieces in a fit of rage… That’s one week of my life I want back…