Powercolor 7950's, engine/memclock jumping around?

[craslovell]

Hi all,

I have a rig with three of these installed: PowerColor AX7950 3GBD5-2DHV4 Radeon HD 7950

Also 8GB system ram, 6 core AMD proc, and thermaltake toughpower grand 1200W gold psu.

Regardless of if I am mining sha256 or scrypt, I noticed the engine and memclock speed hopping around in cgminer. For example, if I set --gpu-engine 1100 --gpu-memclock 1600 and start cgminer, when I look at the speeds of any card it will show a higher voltage and the full speed, and a second later it might drop down to an engine speed of 825 clock speed of 1100 and the voltage will drop slightly. My overall average hash rate isn't bad, but I've configured several other machines for people I know and I've never seen this.

Perhaps I'm just being a noob?

One thing I will say about these cards is the lack of reference cooler seems to mean it is prime for cooking an egg on. I can only average 530MH/s KH/s from each card in order to keep them 80c or below (one of them sits around 73c). This includes a small turbo box fan sitting behind them blowing air over them, AND being positioned two feet below a central air vent so a/c is flowing near the cards (open air bench case).

Any suggestions are welcome, I feel like I could squeeze at least another 10% production out of these things!

Thanks in advance 

[1714497448]

1714497448

[1714497448]

1714497448

[1714497448]

1714497448

[greaterninja]

i would suggest using msi afterburner and the ati****.dll and creating a proper msiafterburner config.

search google or the forumns on how to downclock your memory, voltage, etc.


IMO, if temps are a huge issue go BTC route and downclock memory.


I am also gonna assume you are using PCI-E risers.   Certain cards require a lot of power and they will affect mutiple cards when more than 1 pci-e riser is used.
This will cause gpu performance to spike and the cards to crash easier.


sorry for the typo but i have very little time to help you out.

[camaro69327]

this may just be a question for the cgminer thread ...but.

From what i understood, first you have to set --auto GPU & --Auto Fan, then you need to set a range for the Engine and Fan as a comma separated. Also you would need a temp target. This is all in the Read-me in the cgminer folder, have a look it is one powerfull ass program.


--auto-fan          Automatically adjust all GPU fan speeds to maintain a target temperature
--auto-gpu          Automatically adjust all GPU engine clock speeds to maintain a target temperature
"gpu-engine" : "900-1000,950-1000",
"gpu-fan" : "20-80,20-80",
"temp-target" : "70,70",

Adjust above to suit.

I mine with a temp target, and when a miner is first started it takes awhile for it to "settle" in at the temp requested . it does work great tho.

 

[craslovell]

Thanks for the advice guys, but I think it was just something with the cheapo powercolors. I upgraded to Sapphire Vapor-X 7950s and they are running like champs at 1100 engine and 1500 memclock at 1640KH/s 

[computerparts]

jump around jump around get up get up and jump around

[ScaryHash]

I had to send 2 out of 3 of those Powercolors back. Only one of them works as it should (knock on wood).

They did exactly what you described. The reason for that constant whine and throttleback is that they overheated on and off because the fan basically would not go over about 3300 rpms.

So, they would sit there whine for a while, overheat and then throttle back.

They also do that if you have turbo enabled. I used SapphireX but it does not help if the fan (or fan controller) goes out.

Well, live and learn. The one that works will do 1125 mhz gpu clock easy, so the benefit to them seems to be that they are unlocked.

Not a good fan design IMHO.

[craslovell]

I had to send 2 out of 3 of those Powercolors back. Only one of them works as it should (knock on wood).

They did exactly what you described. The reason for that constant whine and throttleback is that they overheated on and off because the fan basically would not go over about 3300 rpms.

So, they would sit there whine for a while, overheat and then throttle back.

They also do that if you have turbo enabled. I used SapphireX but it does not help if the fan (or fan controller) goes out.

Well, live and learn. The one that works will do 1125 mhz gpu clock easy, so the benefit to them seems to be that they are unlocked.

Not a good fan design IMHO.

I agree, the fans on those things were pretty anemic. It barely moved any air. For an extra $20-$30 you can get a far superior card. The Vapor-X's seem to be running excellently so far. Temps are much lower too, sitting around 72-73c. I will keep my fingers crossed and hope they last me a long time!

[zvs]

I had to send 2 out of 3 of those Powercolors back. Only one of them works as it should (knock on wood).

They did exactly what you described. The reason for that constant whine and throttleback is that they overheated on and off because the fan basically would not go over about 3300 rpms.

So, they would sit there whine for a while, overheat and then throttle back.

They also do that if you have turbo enabled. I used SapphireX but it does not help if the fan (or fan controller) goes out.

Well, live and learn. The one that works will do 1125 mhz gpu clock easy, so the benefit to them seems to be that they are unlocked.

Not a good fan design IMHO.

I got one powercolor and it works fine.  It's running at 1200 core/185 memory.

But then I guess I don't mess with those bizarre alt-coins that destroy video cards

well, my fan is going 4800RPM at 80%

[craslovell]

I had to send 2 out of 3 of those Powercolors back. Only one of them works as it should (knock on wood).

They did exactly what you described. The reason for that constant whine and throttleback is that they overheated on and off because the fan basically would not go over about 3300 rpms.

So, they would sit there whine for a while, overheat and then throttle back.

They also do that if you have turbo enabled. I used SapphireX but it does not help if the fan (or fan controller) goes out.

Well, live and learn. The one that works will do 1125 mhz gpu clock easy, so the benefit to them seems to be that they are unlocked.

Not a good fan design IMHO.

I got one powercolor and it works fine.  It's running at 1200 core/185 memory.

But then I guess I don't mess with those bizarre alt-coins that destroy video cards

well, my fan is going 4800RPM at 80%

Bizarre alt coins? You mean scrypt based coins because of the high mem usage? 

[ryantc]

Thanks for the advice guys, but I think it was just something with the cheapo powercolors. I upgraded to Sapphire Vapor-X 7950s and they are running like champs at 1100 engine and 1500 memclock at 1640KH/s  

er.........that's not true

I have exactly the same card, actually exactly the same number of cards in my rig, and it's hashing @ 1640 like champs @ 1.013v with significant lower frequency then your Sapphire configuration.  All on risers.
You just need to find those cards sweet spot, it's doable.

the only cons of this card is the fan noise, that kills me
just swap to accelero Xtreme Plus II, and I never see 70C again 

[craslovell]

Thanks for the advice guys, but I think it was just something with the cheapo powercolors. I upgraded to Sapphire Vapor-X 7950s and they are running like champs at 1100 engine and 1500 memclock at 1640KH/s  

er.........that's not true

I have exactly the same card, actually exactly the same number of cards in my rig, and it's hashing @ 1640 like champs @ 1.013v with significant lower frequency then your Sapphire configuration.  All on risers.
You just need to find those cards sweet spot, it's doable.

the only cons of this card is the fan noise, that kills me
just swap to accelero Xtreme Plus II, and I never see 70C again 

What numbers are you running? I have my sapphires averaging 1,925KH/s all together at 73c now