Help with my new 6970's?

[yochdog]

I just built a new rig last night with 3x6970, and I would like to ask for some assistance.

I have the 3 GPU's successfully set-up in crossfire config, windows finds them all just fine, and GUI miner is doing its thing with all 3.

My issue is with over-clocking and MH/s.  I am always seeing on this board that 400+ MH/s is the standard for 6970's.  Unfortunately, all I am getting is about 360.  I am clocking them at 910 MHz at the moment, as anything over that and I usually end up with a frozen machine.

Anyone have some experience with getting a stable overclock that could lend some advice?  I would like to get up to 950 Mhz, then maybe I could get the magical 400 MH/s per card.

THANKS!!

Win7 pro 64 bit
sempron CPU
4 GB ddr3 RAM
1000 watt PSU
ASrock MOBO

[Soak]

With my two 6970, I can reach ~390 without overclocking (phoenix + phatk tweaked).

• Memory: 401 MHz (for reduce temp by 10°C).
• Core: 880 MHz
• Power: default

Normally, you don't need to overclock your cards (or a little to reach 400).

[deepDown]

Have you tried using the last version of phoenix (1.50) and phatk kernel? They seem to work the best with Radeon 11.6 and 11.7 drivers.
Also you should check which AGGRESSION or -f settings you are using. VECTORS, BFI_INT also can make quite difference.

Check this thread:
http://forum.bitcoin.org/index.php?topic=32496.0

And, in a 3 card rig I would set fan speeds to pretty high 85-90% so they do not overheat. You definitelly want to be under 90 celsius all the time.


cheers

[yochdog]

I am using GUI miner......is that part of the problem? 

[deepDown]

I tried Diablo, GUI miner and phoenix and phoenix works the best for me.
Though the guy in the thread I linked uses GUIminer so it shouldn't be a problem.

But there is an option in GIUminer to set the kernel it uses and the flags for the kernel - so play around with that and see the results. Most of the guys in Mining Hardware Comparison list post their flags so that is a good starting point and the thread from my previous post has them somewhere I think.

[yochdog]

Where do I choose which kernal to use within GUIminer?  I found the flag no problem (thanks!), but am struggling with the Kernal.

Thanks all. 

[dikidera]

Crossfire decreases mining performance, so disable it. However with that single core semprom and windows....
Dont misunderstand, i love windows, but with a single core semprop you will have 100% cpu usage.

[ToriAmos1963]

Make sure you set the "Power Control" setting in AMD Catalyst to +20%.  If I leave mine at 0, I get a speed increase up to 900 MHz, but then the speed goes down.  With the "Power Control" setting at +20%, I can overclock to 950 with 70 degree temps and 420 Mhps using the bitminter client.  Check out this thread:

http://forum.bitcoin.org/index.php?topic=22432.0

[yochdog]

Thanks everyone. 

Deepdown, I would like to shoot you a donation for helping me out.....you got me an extra 500 MH/s (I have a LARGE farm).  Give me an address if you like. 

[ToriAmos1963]

  So, who is the lucky recipient of the donation?

[deepDown]

Thanks everyone. 

Deepdown, I would like to shoot you a donation for helping me out.....you got me an extra 500 MH/s (I have a LARGE farm).  Give me an address if you like. 

You are mostly welcome!
Here is my address: 1348HX3hrNjuyzwBMoHPJJ1jqB9FXvpZ1N

And if you are just starting, I feel compelled to give u an advice that got me more BTC than better kernels:
Set each card to two(or more) pools -means: just run two instances of a miner directed to different pools. That way if one pool goes down, and sometimes they do even for a whole day, it will automatically mine on the other. And you loose no time(money stalling

[yochdog]

thanks Deepdown....I will send it tonight.

One other question to anyone who knows:  Dikidera said that Crossfire decreases performance?  Can anyone confirm this?  And if I take off the crossfire connectors, will Windows still recognize all 3 GPU's? 

I have had trouble in the past with multiple cards being found. 

THANKS! 

[dribbits]

thanks Deepdown....I will send it tonight.

One other question to anyone who knows:  Dikidera said that Crossfire decreases performance?  Can anyone confirm this?  And if I take off the crossfire connectors, will Windows still recognize all 3 GPU's? 

I have had trouble in the past with multiple cards being found. 

THANKS! 

Everything Ive read says crossfire will be a bit slower. Windows will see all 3 without the connector, both my PCs have three and they were pretty painless to setup.

[runlinux]

if you use the 11.7 (beta?) drivers from ATI, you dont need to use the crossfire cables, OR dummy plugs.

just a heads up. my one rig that isnt b*tchy, uses them and i dont even have a display plugged into either card. i use teamviewer to control my rigs [from my iphone].

[jpinconline]

I also have 2 6950s out of crossfire with dummy plugs using teamviewer and it works great. I see about a 20mhash better out of crossfire but more than that the mhash on each card jumps around ALOT more in xfire. on 11.7 release or 11.8 (beta) you should not need dummy plugs. I have been using the 11.8 drivers for a couple days and havent noticed much if any of a performance gain... but I can use hardware accelerated video aka youtube, vlc, powerdvd while mining and it not locking up my comp. driver does seem a bit buggy though. def worth trying though

[bridgeman]

Along the same lines, I was under the impression there were a significant number of people who only get ~360 out of 6970's... Is that not true? Am i doing something wrong? I followed all the advice in this thread, but phoenix only boosts it to ~370-380.

I thought it was my newer pcb design causing my comparative slowness. I found there are two reference board designs, and the second generation seemed to be the only thing i could get toward the end of may when i bought. Ideas?

[ToriAmos1963]

Along the same lines, I was under the impression there were a significant number of people who only get ~360 out of 6970's... Is that not true? Am i doing something wrong? I followed all the advice in this thread, but phoenix only boosts it to ~370-380.

I thought it was my newer pcb design causing my comparative slowness. I found there are two reference board designs, and the second generation seemed to be the only thing i could get toward the end of may when i bought. Ideas?

Did you change the "Power Control" settings in AMD's Catalyst driver and overclock your card?  I have a newer 6970 and get 420.