[SOLVED] 4870x2 one core at 83Mh/s other core at 54Mh/s

[jarekb]

I've got a 4870x2, but the second core is performing much slower then the first. Based on the graphics card comparison chart I should be getting around 180Mhash/sec, but I'm averaging 135-140. Any ideas why the second core is under performing?

System Specs
Video:  Sapphire ATI Radeon 4870x2 (not overclocked)
CPU:  Intel Q9550@2.83GHz (not overclocked)
Mobo: ASUS P5Q Pro
RAM:  8GB (4 x 2GB) DDR2 800 (PC2 6400)
HD: WD6400AAKS x2
PSU: Corsair CMPSU-750TX
OS: Windows 7 64
Driver: Catalyst 11.5
OpenCL: SDK 2.4

EDIT
Forgot to add that the miner I'musing is phoenix with these parms
phoenix -u http://worker:pass@btcguild.com:8332 -k poclbm DEVICE=1 AGGRESSION=4

[1714107026]

1714107026

[1714107026]

1714107026

[mewantsbitcoins]

Sorry my post was a mess so I decided to rewrite it

Download newest pheonix miner with new kernel, up the aggression, try vectors and bfi_int, different worksizes etc. It's more of a trial and error to get the best results for your system.
You may also want to download msi afterburner and enable unofficial overclocking. Lowering your memory clock will reduce the temperature and increasing your core clock will increase the hash rate

Use two separate workers for each card
You should start your miner with something like this:

phoenix -u http://worker0:pass0@btcguild.com:8332 -k phatk VECTORS BFI_INT DEVICE=0 AGGRESSION=12 WORKSIZE=128
phoenix -u http://worker1:pass1@btcguild.com:8332 -k phatk VECTORS BFI_INT DEVICE=1 AGGRESSION=12 WORKSIZE=128

[jarekb]

I am using two instances from two separate directories (read that was good to do somewhere). I don't bump aggression up over 4 because pc becomes unusable at that point. But at same aggression, shouldn't both cores run at same speed?

[SSJ3 Mario Brothers]

I am having the exact same problem with my HD 4870X2, also a Sapphire brand. I know why, just not how to fix it yet: When a core is not being used, it downclocks itself to save power, however sometimes certain programs, such as the bitcoin miners, cannot trigger it to go back to full speed. I suspect using a third party program to lock the card at full speed would work; I don't know of any that work, but I'm going to try MSI Afterburner per mewantsbitcoins' suggestion!

Also, just fyi, if you have two 4870X2s like I do, only the first core stays overclocked and the other three are all stuck at around 54 Mh/s.

EDIT: MSI Afterburner isn't doing it, but I do enjoy the dynamic fan control feature

[jarekb]

I'll try messing around with MSI Afterburner when I get home, but if it doesn't work is there another program that will let me adjust my graphics cards settings?

[jarekb]

Changing settings in MSI afterburner or CCC for the GPU core clock didn't have any affect. Google around a bit and found this old post from the folding@home guys where RivaTuner was recommended.

Changed settings using RivaTuner and was able to get both cores core clock running at 800MHz. In this post post there's a pic showing where to change the settings.

Settings on both cores are
Core Clock 800MHz
Memory Clock 450MHz

Currently getting 88 Mhash/sec on each core, which is much closer to what the graphics card comparison chart has listed. With these changes running at ~176 Mhash/sec vs the 140 I was at before. I might bring down the core clock to 750 or 700 since the temps are hanging around 96-98 degrees.

[SSJ3 Mario Brothers]

That worked for me too! Thank you very much for the link