Optimizing ATI performance, 6950 in particular

[Grinder]

Hi, I'm new to the Bitcoin community. I started last week, and I thought I'd share my experience with optimizing performance on my 6950 under Windows. I'm currently getting 324 Mhash.

USE THEM ON YOUR OWN RISK. I TAKE NO RESPONSIBILITY FOR ANY DAMAGE ANY OF MY SUGGESTIONS MAY CAUSE. But then I'm fairly anonymous and in a country where they would just laugh at you if you tried...

General tips

Overclocking (potentially dangerous to your card, use with caution)
Get MSI Afterburner. Install it, then open the file MSIAfterburner.cfg in the Afterburner directory in notepad. If you use Windows 7 and possibly some other versions, you need to run notepad as Administrator, otherwise you will not be allowed to save it.

Make sure the ATIADLHAL looks exactly like this:

[ATIADLHAL]
EnableUnofficialOverclocking   = 1
UnofficialOverclockingEULA   = I confirm that I am aware of unofficial overclocking limitations and fully understand that MSI will not provide me any support on it
UnofficialOverclockingMode   = 2
AccessibilityCheckingPeriod   = 0

This will allow you to overclock the card more than specified by the driver. It will also allow you to control the fan, which is important to keep the temperature down. I prefer staying under 80C.

The normal frequency on my card is 800 MHz on CPU and 1250 MHz on memory. For mining you want the CPU to be as high as possible. Memory on the other hand is hardly used at all, so it should be low to avoid adding unnecessary heat and power consumption. My current speed is 890/500, giving about 324 Mhash. It seems to work at 900 but crashes at 910, so I give it a bit extra headroom.

You need to figure out how much your card can take on your own. Do small increments (5-10 MHz) and let it run for a few minutes. Eventually it will freeze your computer, which means you've reached your limit. Back down 15-20 MHz and keep it there.


poclbm parameters
Just -w 64 without -v gives the best performance with my 6950.


6950 specific
I do not recommend using the 6970 firmware. Instead use your original firmware, but modified with the "shaders unlock" patch. There have been several reports of permanent damage, probably because of the different voltage and timings used in the 6970 firmware. It will also make the card use more power, which means higher cost and quite a lot more noise from the fan.

To patch, download these files:
http://www.techpowerup.com/downloads/1920/HD_6950_to_HD_6970_Flashing_Tools.html
http://www.techpowerup.com/wizzard/Mod_BIOS_HD_6950.zip

Unpack both them and download this file: http://pastebin.com/fLTmqWby and save it as flash_to_6950mod.bat to the same directory (flash_to_6970.bat, flash_to_6950mod.bat and run.bat should be in the same directory). Then run flash_to_6950mod.bat. You need to run it as administrator, at least under Windows 7. What this does is save your current firmware, modify a copy of it, and then flash it back.

After flashing the first time you should make a backup of the directory, to make sure you can flash back the original firmware if you need to. If you like you can also try flashing to 6970 using the appropriately named .bat file. If you want your original firmware back you run flash_back_to_6950.bat.

At 890 MHz I actually get slightly higher performance using the 6950 modded firmware compared 6970 firmware, and to keep it under 80C the fan only needs to spin at 36% instead of 46%. My guess is that the 6970 firmware makes the card uses more power than it can supply,  and starts throttling.

Flashing the modded firmware is pretty safe because the card has two firmwares, one of them read only. If your card stops working after flashing turn it off, flip the switch on the card and reboot. When it has booted and is running, flip it back to 1 and flash back your original firmware.

[1714786354]

1714786354

[racerx]

This link may also be helpful for some more info:
http://www.techpowerup.com/articles/overclocking/vidcard/159

I have a 6950 on route today. Will report back here.

So what client are you running / what OS and what drivers versions etc?

Cheers!

[rmartins]

This link may also be helpful for some more info:
http://www.techpowerup.com/articles/overclocking/vidcard/159

I have a 6950 on route today. Will report back here.

So what client are you running / what OS and what drivers versions etc?

Cheers!

Please, don't follow that article's directions. Those are for flashing a 6970 bios into a 6950 card; such procedure may permanently damage your card, as Grinder writes warns in his post. EDIT: Grinder's guide is the new, safer method.

[racerx]

You do realise that my link links to the download you posted... and the link you posted links back to my link?

Its the same download pack, and the php mod firmware is the same as the one in the batch file!

[rmartins]

You seem to have confused me with OP. We're not the same guy.

I just checked and the pack linked in the article is indeed *one* of the links Grinder posted. However, the php mod patcher isn't in the article, only in Grinder's guide, nor is it included in that pack.

I just wanted to warn people not to follow the the link's steps but Grinder's, since Grinder's guide is for patching the firmware but the link you posted is for flashing the 6970 bios. That is, the guide you link is the old method and Grinder's is the new, safer one.

[Grinder]

I've made no attempt to hide the fact that I'm building on other peoples work, but I left as much as possible of the 6970 stuff out to avoid confusion. My contribution is the modified batch file for flashing a modified 6950 firmware, and the guide it self. I even left the link to the article in the batch file I modified. As I said, I do not recommend using the 6970 firmware, which is what the article is all about.

[rmartins]

Thanks for explaining it more succinctly and clearly than I did. And thanks for the guide.

[racerx]

Yes, I missed the username

THanks for clearing that all up.

[racerx]

Ok, after a bit of a struggle I have my 6950 up and running.

Used grinders mod procedure to unlock the xtra shaders. Worked great thank you

I tried to follow the steps detailed here but using the ppa drivers just didn't work. aticonfig/catalyst couldn't detect the card and I couldn't move on. I tried the stock ubuntu fglrx modules as well and nothing would work on a clean 10.10 install

I then  followed these steps to install the drivers direct from amd, and after a reboot the card was detected properly.

I then jumped back to the first link again, but substituted stream 2.3 for 2.1. I couldnt get 2.1 to work with poclbm. Diablo said here not to use the ati download drivers, and that I would need stream 2.3... so I dont know what the right answer is really.

pyopencl compiled nicely, and I've been running polcbm connected to slush's pool all afternoon.. ended up with a small room heater next to my feet now

~310000khash/s

-w of 64 128 and 256 don't make any noticeable change
-v jumped it from ~260000khashs/s to ~310000khashs/s
-f2 is what Im using as the PC is a spare server and not needed for a gui.

Im going to start bumping the clock speed as per this thread here and will report back.

Anyone else running 6950's with input? Im not sure if I'm using the correct driver versions (stream 2.3 & catalyst 11.2) but I guess if its stable and generating enough hashs's then its probably ok.. What are other 6950's getting?

Im new to the pool mining too, Im seeing this, but no coins yet... all normal?

Code:

racerx@fry:~/Downloads/poclbm$ ./poclbm.py -u xxx --pass=xxx -o mining.bitcoin.cz -p8332 -f2 -w256 -v -d0
16/02/2011 16:25:52, b7402f1a, accepted                     
16/02/2011 16:25:56, 38b477ca, accepted                     
16/02/2011 16:26:03, d518754b, accepted                     
16/02/2011 16:26:15, bee6b69d, invalid or stale             
16/02/2011 16:26:22, 4df8f54a, accepted                     
16/02/2011 16:26:32, dc3e84ae, accepted                     
309385 khash/s

[racerx]

The normal frequency on my card is 800 MHz on CPU and 1250 MHz on memory. For mining you want the CPU to be as high as possible. Memory on the other hand is hardly used at all, so it should be low to avoid adding unnecessary heat and power consumption. My current speed is 890/500, giving about 324 Mhash. It seems to work at 900 but crashes at 910, so I give it a bit extra headroom.

Take it the unofficial over-clocking stuff enabled you to go higher than 840mhz?

Im getting ~320000khash/s now at 840Mhz, but cant push it any higher than that. Have you generated coins in linux with this card?

[Grinder]

I'm currently running a 5850 card under Debian Squeeze with stream 2.1. I tested it with the 6950 as well. It worked fine, so it shouldn't be necessary to use 2.3. I downloaded the drivers from AMD and installed to /opt/ without building packages, mainly because it refused to build one.

I've been trying to find a solution for the overclocking problem for days, so I think it's safe to say that going past the AMD imposed limits is not possible under Linux. You would be able to do it with the 6970 bios, though, because it's limits are higher. I ran mine with the 6970 firmware for several weeks with no problems, but as I said it's more risky. The best you can hope for is probably 5% higher performance.

I'm using polcbm on Linux as well, never could get Diablo to run. The -f parameter has a strange effect with my setup. If I set it to 1 the cpu usage on top will be zero, but the load will grow indefinitely. If I set it to 30 cpu usage will be 50%, but load stays below 0.1. You might want to keep an eye on that.

[rmartins]

I think the only way to go past the 840 MHz limit (besides flashing a 6970 bios) is flashing the Asus bios, according to Techpowerup.

Maybe a future version of the Radeon Bios Editor will allow editing the overdrive limit, so we can just modify our card's bios, just like with the shader unlock. That'd be the best option, imo.

@racerx: Slush added a two hour delay for any blocks found by the pool in order to avoid cheating by malicious users. Give it a few hours and you should see some rewards in the 'My Account' section in the pool's site. When the confirmed reward is over the threshold you set, it should be sent to you.

[racerx]

840 isnt too bad really.

I was getting ~320000 with any -f from 1->30 but cpu was spiraling out of control. I changed it to -f40 and now load is a steady .4 with a hash rate of ~318000. Things seem much more stable like this.

I also watched gpu temp and fan speed closely for a while. GPU temp was flucuating from 89c->92c with a fan speed of 40%->55%. I ended up setting it to 65% and GPU temps have leveled at 75C->76.5c.. with a 1c rise in 1 hour. Not sure what the best speed it going to be, but 90c is a little to hot for my liking.

[JWU42]

Just installed my HIS 6950.

Using latest poclbm w/ gui front end

passing nothing - 230 Mhash
passing -v - 270 Mhash
No difference between w64 or w128

using -v -w128 -f2 = 281Mhash (only feasible when away at work)
using -v -w128 -f30 = 273 Mhash

Haven't messed with unlocking shaders just yet - maybe tomorrow 

[JWU42]

Flashed the HIS Shader Only unlock - now at 304 Mhash w/ -v -w128 -f2

OC to 890 I hit 340 Mhash 

[os008]

Flashed the HIS Shader Only unlock

I thought they were laser-cut. Anyway, that's a great boost in performance, nice work.

[true]

Flashed the HIS Shader Only unlock

I thought they were laser-cut. Anyway, that's a great boost in performance, nice work.

Why would you think that? It's been widely reported that reference 6950s have identical PCBs to 6970s, and there are various unlock methods available. The chips seem to be identical, with perhaps better bins on the 6970s but this isn't proven. 6970s are run at higher voltage by default, though. I've unlocked two of my 6950s. (Have a 1GB model for a specific machine and there aren't any known public unlocks yet, if ever - this one MAY have hardware changes to prevent it.)  Will unlock three more 6950s after they're delivered.

[os008]

It's been widely reported that reference 6950s have identical PCBs to 6970s, and there are various unlock methods available.

It's been a long time since I heard of successful shader unlocks. Guess the 6950 is bringing it back.

[travex]

For those who having trouble with increasing voltage for xxx HD6950. I'm using Sapphire HD6950 with custom shader unlocked, using MSI afterburn latest version I can raise my GPU vcore to 1.300V without any problem. My card is running at 1000/900 (core/mem) happily, 380K hash is it.

[JWU42]

I get nervous bumping the voltage that much...

Nice OC though!

I am at 1115mV and haven't tried past 890 as I am at 75C with the fan at 50% (loud).  I do have a 5770 in the case as well so the temps would be lower without that card right next to it.  However, I can 't OC the 6950 enough to make up the 172 Mhash I get from the 5770