Title: [LTC] 3x 4x 7950 need help Post by: e521 on April 26, 2013, 12:43:32 PM I am trying to set up 4x7950
gigabyte windforce v2 flashed bios for 1.090v 13.3 beta cgminer 2.11.3 w7 64bit, 8gb in a sigle stick pci risers x1 to x1 to the cards At the moment I have 3x on a cheap gigabyte mobo which doesn't recognize the 4th card (shorting not attempted) I bought an MSI Z77A-G45 and I will try it tonight to see if the mobo is the problem, I hope so ::) I use an xfx 1250w gold, 3x at 1000/1250/+20% run stable at 750w from wall I can run stable each card individually to 660kh with 1125(55)/1450/+20% I 19 tc 16384, with or without risers. When I put 3 together I cannot go over 595-605kh each, (600/550/600 reported on pool) with 1000/1250/+20% temps about 65-72c with fan 60% At the moment I run guiminer with this cmd: cgminer.exe --scrypt -u x-p-x o x --gpu-platform 0 -d 0 -w 256 -v 1 -I 20 -g 1 -l 1 -T --thread-concurrency 21712 cgminer.exe --scrypt -u x-p-x o x --gpu-platform 0 -d 1 -w 256 -v 1 -I 20 -g 1 -l 1 -T --thread-concurrency 21712 cgminer.exe --scrypt -u x-p-x o x --gpu-platform 0 -d 2 -w 256 -v 1 -I 20 -g 1 -l 1 -T --thread-concurrency 21712 I know a lot of people can keep 1 card at 660kh stable, I also can but what about 3 or 4 cards? What's your hashrate/clock/mem with 3 or 4 7950? Why do I get mixed results between 1 card and multiple cards? is it the mobo which cannot keep it ? or maybe the psu (I doubt this)? I want to squeeze every single hash from these cards, I know 1750-1800kh is good for 3 cards but I am more looking at 650kh each card. So, is it possible? Thanks :) Title: Re: [LTC] 3x 4x 7950 need help Post by: Nutnut on April 27, 2013, 01:45:22 PM I had exactly the same issue when i upgraded from 2 windforce 7970 to 4 on a GA-990FXA-UD3. Was losing about 70Khs per card. Bizarrely, once i removed the additional cards i was still 70Khs down. After pulling my hair out I totally blew away the os (Win7) and rebuilt with all 4 cards in... Been fine ever since. Have no idea why! Maybe worth a shot...
Title: Re: [LTC] 3x 4x 7950 need help Post by: e521 on April 27, 2013, 02:29:22 PM I have rebuilt my rig with a msiz77a-g54, 4 cards running at 605/605/610/580, WU=92%
It seems stable but I think I need at least 1 power riser to be sure Nutnut what's you stable hash for 4x7950? Title: Re: [LTC] 3x 4x 7950 need help Post by: Nutnut on April 27, 2013, 02:50:23 PM current averages:
Rig 1 - 3.022Mh/s Rig 2 - 3.019Mh/s Rig 3 - 2.996Mh/s - Hmmm need to fiddle with this one me thinks. Rig 4 - 3.004Mh/s Title: Re: [LTC] 3x 4x 7950 need help Post by: e521 on April 30, 2013, 02:26:43 PM You are not talking about 7950s, I have never seen 750kh/s per card
Maybe you have 5 cards This is mine, it's rock solid but not I am just at 600kh http://i42.tinypic.com/2mcehk3.jpg Title: Re: [LTC] 3x 4x 7950 need help Post by: Nutnut on April 30, 2013, 03:20:46 PM Sorry - talking cross purposes...
I said i had the issue with my 7970s (which is all i run nowadays), didn't notice you asked about 7950's. nedlees to say, those stats are from 4x 7970s in each rig. |