Bitcoin Forum

Hi Guys,
I've been having a number of problems setting up a litecoin mining rig.
I'm currently running a q6600 rig with 4gb DDR2 and 2x HD6950 cards.  First thing I did was a fresh install of windows 7 64bit. Installed the latest ATI drivers 12.10 (SDK 2.8 ). Then I tried to configure cgminer 2.10.0 and Reaperv13 beta. I did try unlocking the shaders and overclocking the 6950's (up to 925/1350, 1.2v), but since I've been having trouble I've gone back to stock settings.

Here are the configs I've been using:
Reaper litecoin.conf:
host coinotron.com
port 8322
user xxx
pass xxx
protocol litecoin
worksize 256
aggression 16
threads_per_gpu 4
sharethreads 18
lookup_gap 2
gpu_thread_concurrency 5632

Cgminer:
cgminer --scrypt -o http://coinotron.com:8322 -u xxx -p xxx --shaders 1480 --intensity 18 --worksize 128 -g 1 --thread-concurrency 8192

Ok so the first big problem is that I'm getting quite low hashing scores from these cards. Between 290-300kh/s from each max, total 600kh/s(from both cgminer and Reaper). The Litecoin hardware comparison (http://wiki.litecoin.net/index.php/Mining_hardware_comparison) indicates I should be getting another 100-200kh/s per card from these babies. A little disappointing.

Second problem, I read that using catalyst 11.2 and SDK 2.5 may give better performance. I installed these, and then found that both cgminer and reaper couldn't start the Opencl kernel and refused to mine (same configs). In fact the only way I could fix this at all was to just reinstall the catalyst 12.10 driver package. Messing about with the drivers was also frustrating, crashing, blue screens and install failures all over the place.

Third problem, one of my cards seems to be 'unlockable', guess that's unlucky. The other card unlocks the extra shaders then performs about 10% less in mining hashrate. Guess the extra shaders are not any good. (Probably no solution to this one but I just thought id moan about it anyway)

Is there anyone out there who can help me? I've just spent most of the weekend trying to get better performance to no avail :(

I'm not sure if this is the same for windows but on linux it's needed to set these environment variables:
export DISPLAY=:0
export GPU_USE_SYNC_OBJECTS=1
export GPU_MAX_ALLOC_PERCENT=100
cd /opt/miners/cgminer

First, try to increase the aggression from 16 to 18 or 19.

I will try and work out if those linux variable are relevant for windows thanks. Actually that gives me another idea....try linux. I'm even more clueless when it comes to that thought.

Intensity all the way up to 20 only gives a max of 600kh/s for the pair.  :(

For some reason Reaper doesn't like when I input aggression at 20.  19 seems to be my magic number for my 6970s and for my old 5870.

And I've never tried Linux, so I wouldn't know  :D

Sucks should be getting close to 800.


Try that with the core/memory speeds at 800/1250 that gives me ~395kh/s on mine on linux.

Best numbers I've seen all weekend. Thank you.

With some overclocking I might reach 395kh/s per card.
http://i1098.photobucket.com/albums/g374/Negcreep69/Capture_zps0b0c263a.jpg

That is the best clocking for mine I have found seems weird you do not get better than you are on windows. Are you using the machine for anything else while mining? Mine are headless rigs that do nothing but mine.

Nope just mining, fresh install with bear minimum software and drivers on.

I'm going to have to do a Linux dual boot to compare I think. Is Ubuntu a good idea for a noob?

Yes, but if you're new to Linux, I'd say try Linux Mint (http://www.linuxmint.com/download.php) first. Grab the Cinnamon, 64-bit image.

it looks like someone already posted the right settings, but you can also use my thread
https://bitcointalk.org/index.php?topic=117221.0

Have you tried unlocking to 6970 shaders? I get 460 k/hash easily with my unlocked MSI 6950. Core clock 850 mhz.

Cheers, will grab that later. I put Ubuntu on earlier via a windows install....no idea what Im doing. I was stumped at installing the catalyst driver. Much reading to do.


Well, I'm still not really happy. People seem to be routinely getting 400+kh/s with 6950's without much difficulty. I can't get any higher than ~315 per card, and not really any idea why. Over clocking didnt make much difference. Too top it off one of my cards (gigabyte HD6950, reference board i think) runs super hot so it crashes easily. The other is a Sapphire HD6950 Dirt3 edition, much better cooling but it wont unlock the shaders after flashing. I'm just not having much luck.

At the moment it seems I'll have to accept 630kh/s is the most I will get out of the cards. Thanks for the link, I've been there earlier today, it did help quite a lot.


Yeah, I managed to unlock the extra shaders on my Gigabyte card, but it seemed to negatively effect the hash rate by about 10%. I've read that sometimes the extra shaders just aren't very good. Perhaps this is one of those cards that didn't quite make it as a 6970.

Gah, what a frustrating day. Girlfriend is pissed at me for sitting in front of the computer all day :)

I also tried each card on it's own. Same sub par hashing speeds.

Could it be something to do with the motherboard or ram? I am just reusing old hardware here, didn't really research the best components.

q6600@3ghz
Gigabyte EP45- ES3P
4Gb DDR2
700w PSU

Also, has anyone actually compared hash rates with windows 7 x64 and a linux distro?

FWIW I'm on win7 x64.

Your hardware is fine.

Try using gpu-z to check if your GPU clocks are spooling up all the way.

No have pair of 6970 on DS3R version of that mother board same ram and cpu 750 psu they go @ 425kh/s, never used windows for mining so no way to compare.

Edit: And the second card is on pci-e 1x adapter because the second pci-e 16x slot is dead on it even that does not slow it down both cards get same hash rate.

GPUZ indicates overclocking works. But it has little to no effect on my hashrate. Tried 825-950 gpu clock, with voltage increases upto 1.2v. The cards got hotter but it didn't help.


Yeah that was a typo I have the DS3R too.
PCE slots run at 16x for one card or X8, X8 for 2 cards.

Other than trying Linux (which is going to take a while for me learn), I am really out of ideas. I think I'll just have to settle with what I've got unfortunately. They were ebay cards, £220 for 620kh/s isnt too bad I guess.

Me too though the linux is not that hard to do if you have ever installed an os should be simple to get it on machine and most guides can be pretty much cut'n'pasted into a terminal window to finish what you need done to mine.

Thanks for your help guys. I will update this thread if I get any difference with Linux. Will take me a couple of weeks to find the time though with the holidays coming up.

I'm having this problem too now after updating my driver to 12.10.  Try 12.6 and 12.8 catalyst drivers.

edit: going back to 12.8 doesn't fix it for me... something is really broken.

Amazing, even after 12.10 uninstall and driver sweeper and 12.6 reinstall, everything is still fucked up.  I'll keep messing with it I guess.

Use linux?

tbh i'd rather fix the problem, since i doubt i'll be the last person to encounter it.

installing 12.11 beta drivers seems to have fixed it

I'll try this later today and let you know...thanks!

No time to play about with linux for the first time, till the new year :(

Yup, don't forget to delete all the old binaries for cgminer (.bin files)

I'm using cgminer 2.8.7 and getting 500 kh/s now on my 6970, thread-concurrency 8000

Thanks man, you're a star. This combination has completely fixed my problems. I'm now getting 395kh/s out of both cards before even trying shader unlocking or overclocking.

Brilliant. :)


http://i1098.photobucket.com/albums/g374/Negcreep69/Capture2_zpsc7568616.jpg

With the shaders unlocked (on one card at least) and both cards OC'd to 900/1300. I'm now pulling 900kh/s.

Sweet.

I love happy endings. ;D

I'h having a poor performance issue as well. I'm on 12.11 beta and have sdk 2.5 installed. When I run CGminer it doesnt even see my 6950. When I run gui miner it seems like there is some sort of speed limiter.. I can hit 400MHs, 450MHs but then no matter what I use it goes back to 350MHs. I have tried 13.1, 12.10 and, 12.11 beta as well as sdk 2.8 and 2.5. I also have a GTX 480 installed if that helps. Any ideas? I'm loosing out on quite a bit :(

I am actually about to buy a 6950 on ebay.. Will the 1gig gigabyte model be able to get 450? or will I have to settle for 350? 

sry to post on such an old thread but I figure it's relevant cause I don't really even have the money to be buying a 6950 let alone the 200 - 7950's I would love to have!!!  So I want to know and haven't been able to find a difference in kh/s between the 1gb and 2gb cards except for in games.. are you guys using 1 or 2 gig cards.. if you're still using 6950's?

So glad I stumbled across this thread.  Same exact thing going on here.  I'll try this later and see what the result is.

Hey thanks for your help bro!  My 6950 will be on it's way shortly!

By the way, did you know that Xubuntu -- or the latest AMD drivers, or CGMINER -- requires a DUMMY PLUG, even in Linux?

Bet you didn't know that!

While I don't have these cards, I have noticed the dummy plug requirement seems to vary. I've used Xubuntu / Ubuntu / Debian / BAMT all with varying cards, on recent drivers and cgminer builds, and never had to use a dummy plug for 1 or multi-GPU setups.

I'm thinking it could be a motherboard/bios thing as well as setting in the OS itself.

Situations may vary of course, but this has been my experience. None of the units in my farm have dummy plugs, or anything connected to them at all except an ethernet and power cable.