This guide involves procedures that may damage your hardware and/or void your warranty, educate yourself and proceed at your own risk.
I take zero responsibility for bricked cards, hardware damage, housefires, explosions, or ninja attacks resulting from the advice given in this guide or your own stupidity
Got 5 posts to kill so I figure I'll write a little guide to OCing this card.
First off the 11197-03-40G is a blue, non-reference PCB with non-reference cooling. Stock clockspeed is 950 with advertised boost up to 1000. Voltage is unlocked!
Like the rest of the 7970s memory clockspeed must be no less then 150MHz under the core clock or you'll get hardware errors out the wazoo, then stability issues.
I'm using cgminer 2.11.3 main .conf settings:
"intensity" : "9",
"kernel" : "poclbm",
"vectors" : "1",
"worksize" : "64",
"gpu-threads" : "5",
"retry-pause" : "5",
"scan-time" : "45",
I'm using the $90 bounty suggestions from this thread
https://bitcointalksearch.org/topic/1btc-bounty-increase-7970-hashrate-on-bamtcgminer-76228 I haven't done my own tweaking yet.
My drivers are 13.1 whql, and I'm testing clockspeeds with MSI Afterburner 3.0.0.
After you install everything you'll want to read tacotime's post and follow the instructions there:
https://bitcointalksearch.org/topic/underclocking-memory-speeds-correctly-on-7xxx-series-cards-with-afterburner-111891Afterburner 3.0.0 has all the features you need to enable unofficial OC in the settings menu, but for some reason it was hit or miss getting them to "stick" and actually work, so I'd recommended actually following the instructions and changing the config file manually. A word of caution: if you're stuck at getting the afterburner config to save in notepad (access denied) reconsider overclocking your hardware and mining in general. It takes some tech savvy to tune everything and settings are unique to each unit, don't just throw someone else's clocks and voltages into afterburner and expect everything to be peachy. That said the answer is opening notepad as admin, then opening the file. (or saving to your desktop and moving it manually, or changing the permissions on the file, or disabling UAC in the registry) I've seen this asked in almost every thread on the subject so I figured I should address it.
Now you should be able to adjust voltage for both memory and core in Afterburner!
Time for the fun part!
Fire up cgminer and keep an eye on the temps until they stop rising. Probably a good time to fire up gpuz as well. Note your hash rate. Probably somewhere in the low 600s. Bump the core clockspeed up by 25MHz, hit apply and wait. Jumping straight to 1000MHz is probably OK at this point since the card is advertised to go that fast. Wait for temps to stabilize and note your hashrate increase. Go read some threads on mining with the 7970 while you wait or mining in general or the horrible things AISCs will do to the difficulty if they ever actually get launched in earnest
. If your system or GPU hasn't crashed and you're pretty sure it's stable bump up the clockspeed again and repeat. 25MHz increments are ok for this early stage. When you get too high you'll probably see the screen flash, cgminer will throw an error and show 0 hashrate. Time to back off a little, 5 MHz at a time, and restart cgminer.
Using the stock voltage I was able to get 1155MHz on the core, and it ran stable 10+ hours overnight. 1160 would crash after 10-15 min.
Now it's time to bump up the voltage!
Overvolting can be dangerous and damage your hardware! If you're new to the concept I'd recommend reading this thread before continuing:
http://www.overclockers.com/forums/showthread.php?t=384756All set?
Afterburner shows voltages in millivolts (mV) typically you'll see people talk about GPU voltages in full volts i.e. 1.17 (which is 1170 mV). The stock core voltage for this card is 1175 mV. I started by bumping it up to 1200 mV and got up to ~1170 MHz on the core. Repeat as before, but give longer to test stability and use much smaller increments like 5 or 10MHz. Keep an eye on your temps! I'd start to back off at anything over 90C, although how much you push it is up to you. 85C is usually considered hot.
Currently running stable at 1190MHz with 1250 mV on the core giving me 710+ MH/s. I was able to go over 1200 MHz, but the temps were too high for my liking and I wasn't seeing much in the way of gains. My room is pretty hot right now and I'm waiting on a better fan for the inside of my case (one that blows directly at the PCI cards, mounted behind the HDD bay) before I push it further.
So far I haven't undervolted the memory, but I have it clocked 150 MHz less then the core at 1040 MHz. I don't know how power efficient this is yet, but I pay flat monthly for power (apartment is master-metered) so it's not a priority to me at this point. Eventually I hope to update this with all that stuff and try pushing the clockspeed a bit more once I optimize airflow in my case.
Thanks for reading, hope this helps!
