Topic: Guide: OCing Sapphire 7970 3GB OC with Boost ( 11197-03-40G ) ~700MH/s (Read 3638 times)

Yeah there should be an option in your BIOS to default to integrated graphics, possibly in a "north bridge" section. It might also just work if you plug your monitor into your integrated graphics port. I default to PCIe and use a cable from each card into the DVI and HDMI on my monitor so I can still game if I feel like wasting mining time The cables are also an easy replacement for dummy plugs if you have spares laying around. If you select the onboard graphics in the bios you might not be able to tweak some OC settings (I wasn't able to change voltage for example, although there might be some way to overcome this, flashing a BIOS with your tweaks would probably work, but that comes with its own risks and warranty issues). It might vary by motherboard too. When I boot I have all "monitors" on so afterburner can apply my OC, then I disconnect the display coming from the mining card in the windows screen resolution panel (where it says extend my desktop, etc.). That way the card isn't doing any extra work rendering an empty desktop. When you do that though you can't track temps or change the OC. There might be a way to overcome that too that I don't know of. I make things a little easier on myself by setting up profiles in ultramon (not freeware) so I can do it with 2 clicks. Sorry for the wall of text, but I'm a bit tired and just walked my mom through uninstalling/reinstalling IE over the phone.  My mind is about as orderly as a bowl of noodles right now. I've been maxing out my OC so I'll probably post my final numbers tomorrow if it survives mining overnight. I was able to get it up to 740+ avg, but the OC was unstable with my temps well under control so I think I've found the ceiling for this particular card.

Thank you for the help.

I'm using the 7970 to mine and display my desktop, so that makes sense. I have a feeling I get better Mhash/s when the monitor is off, because the fans on the GPU sound different as soon as I turn the monitor on.

The tasks I do on the computer usually don't require the help of the 7970 --- motherboard has onboard 256mb graphics --- is it possible to use the onboard graphics for my display while the 7970 is dedicated to mining?

Thanks for the tip, I switched kernels a few hours ago and I am getting 1-2 Mh/s more (avg). Not 10% so I guess mileage varies, but every little bit helps.
[EDIT] I noticed that I was getting a lot of rejected shares running diablo, not sure what's up with that. I switched back to poclbm and it seems to have stopped. What clock speeds are you using?


1. Are you using integrated graphics while mining? I get artifacts when I enable the display output on the 7970 while mining, that's pretty normal since you're using 99% of the GPU then asking it to also render the desktop. I doubt it's anything to worry about. I've read multiple places that damaging hardware is nearly impossible unless you overvolt. Keep an eye on the temps though. Coinslut's concerns about temperature and hardware lifespan are valid.

2. I have an NZXT Switch 810 full tower case with stock fans. It's a 10 fan case with 4 fans. The rear exhaust is designed for 2 120mm fans and comes with 1 ~65CFM 140mm fan. I can't exhaust the heat from 2 GPUs fast enough without an upgrade. My temps drop 10c with the side off. It's something that's happening because airflow is a mess, not something I recommend for everyone.

Nice guide, I have this card and might consider trying this.

Two questions:

1. I'm seeing screen fractals (almost always just in the taskbar, nowhere else) when running the card on the overclocked bios bank (1GHz) while bitcoin mining (590Mhash/s). Monitor is nothing fancy, 1280x1024, 19 inch. Running Win 7 and latest driver. Is this normal/okay, and would it be safe for me to follow this guide?

2. Would you think that mining with the side panel of the computer case off would be better for temperatures inside? I do have case fans on the front and back, so I would think it would be a good idea to leave the side panel on to keep the pull of airflow going, but at the same time, having the panel off seemed to work very well at allowing heat to expel right out the side.

Thank you

Interesting I just tried Diablo kernel earlier tonight and didn't notice anything. What settings are you using?
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Nothing special really.

-I 9 -k diablo -v 1 -w 256

Makes sense. Bit of a long term strategy though, I don't think OCing voids Sapphire's warranty and even then when you RMA it you'd have to mention it for them to know. I doubt this'll be a viable mining card after the 2 years runs out, so I'll probably end up selling it before then. Resale + earnings should be enough to buy an AISC. Just my thinking.

Would you mind sharing your clock speeds and settings?

Interesting I just tried Diablo kernel earlier tonight and didn't notice anything. What settings are you using?

At a steady 60c here, I would be worried about lifetime of the card just to get 20% more bitcoin. It will take about a year for you to pay off a new card with that 20% extra. Probably just me.

I found running the diablo kernel increased my output by about 10%.

Why's that? Using those numbers the performance scales linearly with the power draw. Airflow in my case is a mess because the manufacturer included less then half the fans and they're not configured for multi card setups. With the side of the case off I'm getting a steady 78c OCed. 20% more coins now will add up as the difficulty increases.

IMHO better to stick with 580 MH/s underclocked using 20% less power and keeping the heat down)

Haven't messed with the settings lately, although I noticed that workspace 256 preforms the same as 64. I think I may have bumped the voltage a tiny bit. I'm running CCC 13-1 whql. I was using the beta (3?) just fine, but afterburner was driving me bonkers and I uninstalled everything and went with the whql when I reinstalled, mostly because I still had the install file.
I've played with trixx a little, but I wanted to undervolt the memory so I went with afterburner. I still haven't played with undervolting the memory yet though. I was waiting on a yate loon 140mm case fan before I started tweaking again, but it hasn't helped airflow in my case as much as I'd like (I'm running 2 cards on a small MB with bad spacing) so I'm probably going to have to find new 120mm fans for the back to fix the general airflow issues in my case. More money :\

This is what I've read everywhere for this card too, and when I tried dropping it 160 below the core it produced a lot of HW errors for a few min then crashed the drivers.

From what I understand its good to keep the memory down under 150 below the gpu... but im still learning a bit..

why are you oc'ing your memory ? you're doing  litecoins ?

thanks for this, I just got this card and working on getting it past 700 still, have you also tried the sapphire trixx? This allows for adjustments as well and core voltage out of the box, for some reason even though I adjusted the msi afterbuner config I was still unable to adjust the voltage.

this is my current command line

-v 2 -w 256 -k diakgcn -I 9 --temp-target 75 --auto-fan

core at 1155 , memory at 1040.. haven't played with volt adjustments yet.

Have you tweaked your settings lately?  Also what driver or sdk are you running..

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:
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-111891

Afterburner 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=384756

All 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!