Topic: 7950s throttled over 17 intensity Litecoin mining (Read 2373 times)

you might think it's driver but i'm calling Power on this one, either drawing though the PCIe or just right on out of the Kingwing !

your PSU says 1000W right? you know a KingWing isn't going to Run 1000W - you are running 3x cards and a mobo, and a HD?  

cya later KingWing, likely the draw on the Pcie is too much , also does it outright just freeze sometimes?

if so that's power , its happened to me , how i actually tested it was to turn my vacume on , it acted like it was drivers , but its a power draw issue.

that's my best guess,

pull one card out and see if it still does it , (or have you done that already? )  

so just run two , see what happens.

That IS a heat problem. If you're reaching that high on stock clocks, then you can't push those cards any further and need some better cooling.

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

Still thinking about a potential driver issue... Because the default adapter always stays at 99% load while the two others go down, then up, than down... like that. Anybody mining on ubuntu 12.04? If so, what driver version are you using?

The best Power Supply that I have found is the XFX ProSeries 1050W
http://www.newegg.com/Product/Product.aspx?Item=N82E16817207021

Currently running 3x 7950s and have overhead for 1 more atleast.

$190 and its fully modular, I'm very impressed by this power supply.

I'm using XFX Power supply and XFX video cards. 5 year warranty on the power supply and lifetime on the cards. I don't know how the other brands compete.

I run 4x7950 http://www.newegg.com/Product/Product.aspx?Item=N82E16814125414 at ~610khash/s each with stock config and with temp of : 61°C, 77°C, 79°C, 81°C
--shaders 2048 --intensity 20 --worksize 256 --thread-concurrency 21712 -g 1

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

I've seen that happen with too low a voltage, if you haven't changed the voltage I'd look at trying another PSU.

I use corsair HX 850 and it powers 3x 7950's with ease.

Because the default adapter always stays at 99% load while the two others go down, then up, than down...

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

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

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

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.

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

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.