7950s throttled over 17 intensity Litecoin mining

[gabo77]

Hi,

So here is my problem, I hope someone can help me out.

First of all, my rig is composed of 3 7950s at stock clocks with one 1000w KingWing platinum PSU. One video card hooked up to a display and the 2 others to a dummy plug. It is running on Ubuntu server 12.04, cgminer 3.1.1 with latest AMD drivers.

Everything is running without a glitch except when I go over an intensity of 17, problems start at 18. What happens is the card hooked to the external display runs fine and stable but the two others are throttled: once every approximately 10 seconds, they will drop from 515 kh/s to approx. 420 kh/s for a couple of seconds, and then get back to 515 in this particular exemple. I can easily get a single 7950 to 630 kh/s when overclocked but I am far from getting there with all my cards.

I suppose the problem is not one coming from the PSU since at stock clocks and intensity of 18, the power from the wall reads at max 815 w. I should have enough room.

It is neither a heat problems since the cards at those settings are running at 82 celcius max fans under 4000 rpms.

I thought this could be a driver issue, not letting me use 100% of all GPUs all the time to protect them... dunno. I didn't want to start testing bunch of drivers version since this would be really time consuming. Maybe someone knows of a version working better than others? Tried adjusting --gpu-powertune without much luck, though it seems to help a little bit...

No HW errors, rejected shares of 1 to 1.5%.

Any ideas of what would cause that?

Thanks for your help!

edit: export DISPLAY=:0, export GPU_MAX_ALLOC_PERCENT=100 and export GPU_USE_SYNC_OBJECTS=1 are all set.
here are the settings I use in this example: --shaders 1792 --thread-concurrency 21712 -g 1 --lookup-gap 2 --gpu-vddc 1.03
so nothing to fancy, just trying to get stable at high intensity... thx

[digitalindustry]

Hi,

So here is my problem, I hope someone can help me out.

First of all, my rig is composed of 3 7950s at stock clocks with one 1000w KingWing platinum PSU. One video card hooked up to a display and the 2 others to a dummy plug. It is running on Ubuntu server 12.04, cgminer 3.1.1 with latest AMD drivers.

Everything is running without a glitch except when I go over an intensity of 17, problems start at 18. What happens is the card hooked to the external display runs fine and stable but the two others are throttled: once every approximately 10 seconds, they will drop from 515 kh/s to approx. 420 kh/s for a couple of seconds, and then get back to 515 in this particular exemple. I can easily get a single 7950 to 630 kh/s when overclocked but I am far from getting there with all my cards.

I suppose the problem is not one coming from the PSU since at stock clocks and intensity of 18, the power from the wall reads at max 815 w. I should have enough room.

It is neither a heat problems since the cards at those settings are running at 82 celcius max fans under 4000 rpms.

I thought this could be a driver issue, not letting me use 100% of all GPUs all the time to protect them... dunno. I didn't want to start testing bunch of drivers version since this would be really time consuming. Maybe someone knows of a version working better than others? Tried adjusting --gpu-powertune without much luck, though it seems to help a little bit...

No HW errors, rejected shares of 1 to 1.5%.

Any ideas of what would cause that?

Thanks for your help!

edit: export DISPLAY=:0, export GPU_MAX_ALLOC_PERCENT=100 and export GPU_USE_SYNC_OBJECTS=1 are all set.

why do yo uhave the other two hooked to a dummy plug?

you need to post some more specs.

also post your conf file.

[superfastkyle]

you need to add
--gpu-powertune 20
to your config

[gabo77]

why do yo uhave the other two hooked to a dummy plug?

you need to post some more specs.

also post your conf file.

I edited my original post for config. Heard it would help with dummy plugs so I tried. I am having the same problems with or without them.

[gabo77]

you need to add
--gpu-powertune 20
to your config

Tried that, same results.

[gabo77]

why do yo uhave the other two hooked to a dummy plug?

you need to post some more specs.

also post your conf file.

What specs would you like me to provide?

[digitalindustry]

you need to add
--gpu-powertune 20
to your config

Tried that, same results.

Ok do this - its like mixing music - just set everything to zero and start again.

so you run a .Bat file obviously - set it to just start CGminer and only set intensity – I 18

and tell me what happens - so copy your .bat and just run a vanilla one take out the screwing with the voltage and TH and Sharders - if it works , slowly bring things back until you find the problem.

** you can leve the SET group i.e GPU_MAX_ALLOC_PERCENT=100 etc.

[shiv]

So dont run intensity 17?

I run mine at 12, anything higher just throttles or crasches.

[gabo77]

Now with --gpu-powertune 20 PSU is sucking up to 910w from the wall. I am having the same unstable behavior only from the 2 GPUs not hooked. The one hooked to the display is fine.

[digitalindustry]

Now with --gpu-powertune 20 PSU is sucking up to 910w from the wall. I am having the same unstable behavior only from the 2 GPUs not hooked. The one hooked to the display is fine.

was that in response to me?

also I run 4 cards at -I 19,20,20,20

no problems - once every couple of days the pc would freeze - but i'm working on that , have it solved.

also you are very close to your Watt limit i'd say.

[gabo77]

So dont run intensity 17?

I run mine at 12, anything higher just throttles or crasches.

The thing is this rig *should* be able to run full intensity and get better hash rate, so I am doing what I can to achieve it, you know anything over 17 intensity not working isnt normal.

Ok do this - its like mixing music - just set everything to zero and start again.

so you run a .Bat file obviously - set it to just start CGminer and only set intensity – I 18

and tell me what happens - so copy your .bat and just run a vanilla one take out the screwing with the voltage and TH and Sharders - if it works , slowly bring things back until you find the problem.

** you can leve the SET group i.e GPU_MAX_ALLOC_PERCENT=100 etc.

thx digitalindustry, will try that and get back when I have results.

[gabo77]

Now with --gpu-powertune 20 PSU is sucking up to 910w from the wall. I am having the same unstable behavior only from the 2 GPUs not hooked. The one hooked to the display is fine.

was that in response to me?

also I run 4 cards at -I 19,20,20,20

no problems - once every couple of days the pc would freeze - but i'm working on that , have it solved.

also you are very close to your Watt limit i'd say.

Not exactly, just providing more info. I know I am close, I will daisychain another one soon but would like to get everything stabilized by then since I thought I had enough room so the psu wouldnt cause this problem...

[digitalindustry]

"1000w KingWing" - also be a little concerned about any PSU that makes me think of parts of a chicken. and/or hungry .

[gabo77]

"1000w KingWing" - also be a little concerned about any PSU that makes me think of parts of a chicken. and/or hungry .

Haha yeah, well I thought it was a good deal (180$) for a 1000w platinum that had good reviews on the web... But I get you.

[gabo77]

Ok do this - its like mixing music - just set everything to zero and start again.

so you run a .Bat file obviously - set it to just start CGminer and only set intensity – I 18

and tell me what happens - so copy your .bat and just run a vanilla one take out the screwing with the voltage and TH and Sharders - if it works , slowly bring things back until you find the problem.

** you can leve the SET group i.e GPU_MAX_ALLOC_PERCENT=100 etc.

Ok so even with nothing but SET groups and intensity, I get the same behavior. Maybe a little bit better, but still same problem.

[gabo77]

And again, the only GPU that is not affected is the one hooked to the display. Dummy plugs on the others change nothing. --gpu-powertune 20 neither.

[22naru]

what brand are your GPU?... i can help you  with some info  if you have MSI tf3. pacpac

[gabo77]

what brand are your GPU?... i can help you  with some info  if you have MSI tf3. pacpac

They are powercolors. If you have any clues, don't hesitate to share

with aticonfig --od-getclocks --adapter=all I can see that the gpuload gets down to 64%, then back to 99, the back to 64... like that.

annoying!

And this is with --gpu-powertune 20.

[phrozenspite]

How much Ram do you have?  You could be maxing that out possibly

[gabo77]

How much Ram do you have?  You could be maxing that out possibly

I have 8 GB. Didn't check the clock at which the system put it though. Could that change something? I have an Athlon 2