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Other => CPU/GPU Bitcoin mining hardware => Topic started by: Kinetic915 on April 29, 2013, 04:18:20 PM



Title: 3x7950 temp problems
Post by: Kinetic915 on April 29, 2013, 04:18:20 PM
Hello all,

I have 3 7950s hashing around 600 each, the temps between each vary alot however.  All 3 are on 1 foot riser cables above my motherboard, I consistently have a temp issue with the first card, while the other two are perfect.  I have fans on the 1st and 2nd cards, the third needs no fan.

here is a link to the temps:
http://postimg.org/image/r6mktj35z/ (http://postimg.org/image/r6mktj35z/)
http://postimg.org/image/r6mktj35z/

I even tried moving the first gpu off to the side which didn't help the temps either,  Is this because the system is using the 1st one more intensely then the others?

Any help appreciated!  Thanks!


Title: Re: 3x7950 temp problems
Post by: papaminer on April 29, 2013, 04:25:32 PM

I even tried moving the first gpu off to the side which didn't help the temps either,  Is this because the system is using the 1st one more intensely then the others?

Any help appreciated!  Thanks!

not an expert here.. but based on my experience.. i would say yes...


Title: Re: 3x7950 temp problems
Post by: crazyates on April 29, 2013, 05:08:04 PM
Might try taking the heatsink off, and repasting the GPU.


Title: Re: 3x7950 temp problems
Post by: Kinetic915 on April 30, 2013, 02:28:55 AM
#crazyates I might just RMA to newegg before its too late!


heres a picture of my rig:
the red arrows represent air.  Do I have the gpu order correct?  The hottest GPU is #1, being the one on the far left?  Each card is placed in each consecutive pci-e slot.

http://postimg.org/image/z2dajhx61/ (http://postimg.org/image/z2dajhx61/)

Thanks!


Title: Re: 3x7950 temp problems
Post by: MinerLT on May 13, 2013, 08:23:35 PM
same problem here, first gpu is alot hotter than others...


Title: Re: 3x7950 temp problems
Post by: crashoveride54902 on May 14, 2013, 01:40:11 AM
if your using this computer to browse web then yes it uses the first gpu harder...if its a dedicated miner then no all temps should be around the same


Title: Re: 3x7950 temp problems
Post by: ISAWHIM on May 14, 2013, 04:43:40 AM
temp sensors are NOT accurate. They are cheap ball-park values, at best.

Chances are... you have reached a limit of a voltage regulator, or the heat has destroyed a seemingly useless "sensor" from being displayed correctly, or you just have an actual "hot" chip.

Measure the actual temps with an IR temp device. (You can return it when you are done.) They are like $20-30 at tiger-direct or walmart or home depot.

Best solution for reduced temps is to lower your voltage (which will also require a slight clock lowering if you are at an upper-limit for clocks.) That will give you greater cooling than clock adjustments, thus keeping most of your speed and lowering power consumption and heat. (If you know a safe-range of clocks, you can put that range in cgminer, and it will auto-adjust to keep a target temp.)


Title: Re: 3x7950 temp problems
Post by: cdog on May 14, 2013, 11:44:53 AM
Anything under or around 90c is fine, its a GPU not a CPU do some research...


Title: Re: 3x7950 temp problems
Post by: ewitte on May 14, 2013, 01:30:57 PM
When I had the 7950's in the same box the top one would hit 98C and throttle with max fan.  Alone in a system it runs 80-85C at 55% fan.  I'm about to put them in an open system with powered risers so they are not so close.


Title: Re: 3x7950 temp problems
Post by: rob1313 on May 15, 2013, 12:21:35 AM
Hello all,

I have 3 7950s hashing around 600 each, the temps between each vary alot however.  All 3 are on 1 foot riser cables above my motherboard, I consistently have a temp issue with the first card, while the other two are perfect.  I have fans on the 1st and 2nd cards, the third needs no fan.

here is a link to the temps:
http://postimg.org/image/r6mktj35z/ (http://postimg.org/image/r6mktj35z/)
http://postimg.org/image/r6mktj35z/

I even tried moving the first gpu off to the side which didn't help the temps either,  Is this because the system is using the 1st one more intensely then the others?

Any help appreciated!  Thanks!

i have the exact same problem. i have 2 setup's that are exactly the same but 2 has more space between cards then one. it has longer 16x cables so i could move 1 card farther to the side. both a 4 x 7950 box 1 run at 64c Max and box 2 runs at 75c on 1 card all others are 65c and under. i have this card with a 200 mm fan pulling the air off the top so heat dont transfer from card to card and i have a 120mm fan pushing air in from the front of my milk crate so the hot card has fresh air and then i used msi power tune at -2 to keep the card at 75c. but it kill my hash rate on all cards by 70 mh/s any suggestions as to what i should do? all cards have 2 in space between then and there are no cables obstruction air flow. I also had to stick 68 ohm resistors in the card to get it to recognize the card fully power otherwise they would only mine a half speed.


Title: Re: 3x7950 temp problems
Post by: rob1313 on May 15, 2013, 12:22:11 AM
Hello all,

I have 3 7950s hashing around 600 each, the temps between each vary alot however.  All 3 are on 1 foot riser cables above my motherboard, I consistently have a temp issue with the first card, while the other two are perfect.  I have fans on the 1st and 2nd cards, the third needs no fan.

here is a link to the temps:
http://postimg.org/image/r6mktj35z/ (http://postimg.org/image/r6mktj35z/)
http://postimg.org/image/r6mktj35z/

I even tried moving the first gpu off to the side which didn't help the temps either,  Is this because the system is using the 1st one more intensely then the others?

Any help appreciated!  Thanks!

Why do you have 2 cards briged?


Title: Re: 3x7950 temp problems
Post by: roflplatypus on May 15, 2013, 12:42:21 AM
yeah, gpu's can go a lot higher than cpus. my cpu hits about 70c at max load, but the gpus go up to 95c before throttling. (all oc'd) basically, if it's stable, it's fine. enjoy your space heater.


Title: Re: 3x7950 temp problems
Post by: rob1313 on May 15, 2013, 01:24:46 AM
yeah, gpu's can go a lot higher than cpus. my cpu hits about 70c at max load, but the gpus go up to 95c before throttling. (all oc'd) basically, if it's stable, it's fine. enjoy your space heater.
Ok will do I want the card to last 1 year then I don't care really.  Now the card is running

Intensity 4
Engine 950 memory 900
76-78c 44 mh/s
Power turn -1

I guess all I can do is play with it I want to see if it has bad thermal paste but it is a new card just came in mail today. And I don't want to void warrenty or any thing. D you think I would benefit from switching card to another spot and see if the heat follow the card vs spot plugged in?

Thanks for you help with this,


Title: Re: 3x7950 temp problems
Post by: induktor on May 15, 2013, 06:45:13 PM
Hello
I have a similar problem, card 1 (where the monitor is) is about 15 degrees or more above the other two.

My solution (unpopular, i know) was to lower the clock to non-oc setting (850 Mhz) and leaving the other two cards at 925 or 950.
that way the hottest card is stable around 63 degrees
keep in mind that in LTC mining, the danger is the VRM temp, with 63 degrees on the GPU I have 79 Degrees on the VRM !! yikes!
(all degrees in C)
I know, I lost some hashing speed, but the card will live a lot longer :)


Title: Re: 3x7950 temp problems
Post by: miningdude on May 15, 2013, 07:18:40 PM
The volume of air getting pushed past the cards made a difference for me. I use a 20" high efficiency box fan. The other thing to check as was already mentioned, is your thermal paste on the heatsink. Not all cards are assembled equally, unfortunately.


Title: Re: 3x7950 temp problems
Post by: induktor on May 15, 2013, 08:46:23 PM
The volume of air getting pushed past the cards made a difference for me. I use a 20" high efficiency box fan. The other thing to check as was already mentioned, is your thermal paste on the heatsink. Not all cards are assembled equally, unfortunately.

What do you mean? that the factory thermal compound sometimes is bad?, damn!, but if I replace it, what about the warranty?.

I have tried with the antec bigboy 200mm fan, from bottom, top (pulling and extracting) side, front and back, no cigar... every attempt to cool these cards end up making it worse, more temperature, if not in the first in the next card, it seems to be disrupting the airflow somehow.
if you found a way, please post a photo, would be great :)