7950s throttled over 17 intensity Litecoin mining

[gabo77]

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?

[hendo420]

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

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.

[Tigggger]

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

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.

[PeeJWeeJ]

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

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.

I also have seen this happen with voltage/over-clocking issues. Sometimes there's a spot that's just unstable, how do you have the cards clocked?

You could also mess with some of the settings from here https://github.com/litecoin-project/litecoin/wiki/Mining-hardware-comparison

[gabo77]

Tried stock clocks and voltage, undervoltage, overvoltage, can't do. I think I tried all the config possible

I will get this to work on a new windows7 install and get back to you to see if the drivers I was using under ubuntu server had any problems that the windows' ones don't.

If same problem arises, will try with another psu.

[SylTi]

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 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

[gabo77]

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

Still same problem. Thx for sharing your config tho!

[gabo77]

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

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.

Are you overclocking your cards? With my KingWing lazer platinum 1000w I was reading a little over 1000w from the wall when I would start overclocking a bit, that is with 3 7950s. What are your cards? How do you measure that you would have room for a 4th one?

Thank you

P.S: I am looking to buy a PC Power & Cooling 1200w Silencer MK 3 platinum for 4 7950s. I returned the KingWing.

[digitalindustry]

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?

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.

[computerparts]

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

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.

[gabo77]

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?

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.

I returned the KingWing today, I'm getting another one and once it's received, I will then post the results. I am thinking PC Power & Cooling Silencer MK 3 1200w. Not sure if it's worth going with the corsair ax1200wi... it's 40$ more. Still thinking about it. hendo420 also told me about the XFX ProSeries, which I am considering too. Found the corsair ax1200wi for 300$ on NCIX, I'm getting this one. As of now, this rig is not mining until I receive the new psu. Also, I wasn't using powered risers since the motherboard was 3way Crossfire ready, but in my next attempt I will have all cards on powered risers.

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.

Why would the default adapter work flawlessly then? It is not any cooler than the other 2. I've run those cards to 90+ celcius without seeing throttling on my other rig... But I am looking into trying to have better cooling, I know they are a little hot. I've reapplied thermal paste and removed their plastic cases, which helped them get a couple of degrees.

Thx for your insights!