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Other => Beginners & Help => Topic started by: BTC_Noob on January 24, 2012, 08:16:04 PM



Title: Problem running 2 cards - need help!
Post by: BTC_Noob on January 24, 2012, 08:16:04 PM
Ok,

I'm fairly new to mining and have ordered a number of 5xxx and 6xxx cards to get started. So far I have received (2) 5830's and (1) 6850 and have had a chance to play around with them. I have an older AMD Socket 939 board that supports SLI so I can't run any cards in crossfire but I have been able to install all 3 cards successfully...

The motherboard is an older ASUS A8N32-SLI with (2) x16 PCIe slots, they are PCIe 1.0 slots but I'm told this shouldn't matter. The 6850 installed without a problem running SDK 2.4, Phoenix 1.5.2, and the Phatk2 kernel. When I tried to install the 5830's however, the system would not boot which I later found to be a problem with PCIe 2.1 compatibility with 1.x slots but was able to successfully install one of them if I installed it in the 2nd slot...

As for speeds with only a single card, I was able to get the following:

6850 (970 core / 300 memory): 269Mh/s
5830 (980 core / 300 memory): 314Mh/s
5830 (1000 core / 300 memory): 323Mh/s

I'm pretty new at this, however I think these numbers look about right so far...


Now, the problem comes in when I install the 6850 in the first slot and either 5830 in the second slot. If I try to run the monitor on the 5830 I get a bunch of white/black lines on the screen, so I put the monitor on the 6850. I manually adjusted the clock speeds for each card using afterburner and created a separate batch file for each card using (DEVICE=0 and DEVICE=1)

The 6850 is able to maintain speeds between 230-259Mh/s (still slower than the original 269) but the 5830 jumps all over the place ranging from 190-280Mh/s

If I stop either one of the miners, the speed of the other goes back to where it should be (269/323)!?

The only thing I noticed is different is if I open afterburner... The GPU usage fluctuates between 60-99% on both GPU's (more so on the 5830) and mirror each other. For example while Card1 is at 99% - Card2 goes down to 60%, when Card2 goes back up to 99% - Card1 goes down to 60% or so...

Can anyone please tell me what is wrong!? I should also note that CPU usage is also very high but not more than 70% on each core. Are the 32 PCIe 1.0 slots not enough? CPU not strong enough? Or something else entirely??



Flags for each miner are set at:

-u http://user:pass@bitcoinpool.com:8334 -k phatk DEVICE=0 WORKSIZE=256 VECTORS BFI_INT AGGRESSION=11 FASTLOOP=false

I have also tried different aggression settings, nothing seems to change.


Title: Re: Problem running 2 cards - need help!
Post by: dizzy1 on January 25, 2012, 12:12:47 AM
What version of catalyst are you running?


Title: Re: Problem running 2 cards - need help!
Post by: BTC_Noob on January 25, 2012, 01:17:28 AM
I'm running Catalyst 11.12 display drivers with 2.4 SDK/APP


I was messin around with some things since I last posted, I haven't fixed it yet but I found it interesting that when I changed the video boot order in BIOS from:

PCIe1 - PCI - PCIe2   to   PCIe2 - PCI - PCIe1

and also moved the DVI cable from the 6850 to the 5830 and VGA to the 6850 the speeds are back at 100% for the 5830, but have now dropped on the 6850!? I have no way to tell, but I wonder if the DVI connection (vs VGA) is somehow affecting it? Or if the switch in BIOS made a difference?