Topic: Six Card Rig x6 7950 MSI TWIN FROZR 3GD5/OC - page 2. (Read 8125 times)

You have the same motherboards!!! YES!!!! With 6 running?! *hallelujah* That literally just relieved me so much, because I really didn't want to go through the hassle of having to order a different Mobo/CPU setup.

Ok, presence shorts on the thrid x1 slot assuming your counting the northbound (coming from cpu moving down the board) one as #1 then pcix16 then pcix1 # 2 and pcix1 # 3 and pcix16 pci 16 end of board

So I need to presence short pcix1 #3 and pcix16 just under it? Got it. Could you send me pictures of your presence short? I've seen pics on line for a 1x slot, but not of a 16x, or if you could link me to a good pic/diagram.

I have powered x16 to x16 extenders, I have powered x1 to x16 as well, but they were done incorrectly and don't provide the extra 12v I think... None the less i have the 16 to 16 which I know were perfectly, and since I'm using one PSU and its the same one for the mobo I don't need to sever any of the lines.

Yeah I have these MSI cards and they undervolt just fine in windows so hopefully it won't be much of an issue in Ubuntu, any advantages to Ubuntu or Xubuntu?

Any chance you mind emailing or IMing me or some kind of instant communication and we can discuss a little more?

Oh and in regards to the song my gf wrote lol, we live in these new apartments for college students and our walk in closet is actually through our bathroom, so you walk into the bathroom and then theres another door to the closet which is directly in front of the toliet and often open, and in there on the top shelf under an AC vent are all my rigs Lol so she had a clear view of them

I've got two of the exact same motherboard you have, and I'm running six cards each as well.  Using Ubuntu 12.04.2 LTS.  I can't really say anything about Windows vs Linux, I've only been mining in Linux.


Yes, you do need a presence short on the 3rd PCIe x1.  I've got all my cards on x1 to x16 risers (even on x16 slots) and had to do the presence short on that last x1 slot and the x16 slot just under it.
There aren't any additional power lines on the longer PCIe slots, x16 won't have any more than x1 does.  Take a look: http://en.wikipedia.org/wiki/PCI_Express#Pinout - all of the power pins are on the little section before the notch.
On my boards, I use three unmodified and three powered risers.  With my powered ones though, I sever the +12V lines going to the motherboard so that it only pulls power from the molex.  I actually have those powered risers powered off the second power supply.
If you don't sever the lines, you have to plug those molexes into the same power supply that's powering the motherboard.


1600 watts should be enough, I measured one of my rigs with a Kill-A-Watt at about 1500 watts with all six cards running (before playing with voltage).  I actually over-spec my power supplies, each rig has two in the 900-1000 watt range.


There's a mining rig in your bathroom?

Oh sorry forgot the mobo model. Its this one GA-F2A85X-UP4

http://www.amazon.com/Gigabyte-Motherboard-Triple-Monitor-support-Windows/dp/B009L1EOKQ/ref=sr_1_1?ie=UTF8&qid=1370547565&sr=8-1&keywords=gigabyte+fm2

Ok good to know, keep me posted when you get 5 or more running stable, I'd like to know about the details.


Yes it would be more stable, but a simple script to start cgminer when the computer reboots, and a setting in motherboard bios for it to always be on takes care of constant reboots, though I am trying to avoid that all together. And it is extremely more profitable to run x6 cards or more in one rig. The more cards in one rig, the less you spend on infrastructure (mobo,cpu,ram,shell) per card. Which improves the ROI a lot as well.

If I can get 6 stable and it takes me a whole weekend of testing to get it, it'll be worth it. But I don't see your point, it is becoming a huge headache and I've put in(wasted) a lot of time as it is.


I actually have thought about that, I would imagine the bios has an option to downclock it, which would use less volts if I couldn't force a lower constant voltage. That is if were speaking about the memory for the system and not each cards actual memory, the cards stay plenty cool. The mobo/cpu/ram also stay pretty cool. So I don't think its that, but I suppose its worth trying, have you seen info/post anywhere that recommend this? or confirm any kind of results?

 

Theoretically, GD65 should run 7 cards.
https://bitcointalksearch.org/topic/motherboard-of-choice-for-6-or-more-gpus-186877
https://bitcointalksearch.org/topic/1-btc-bounty-claimed-get-6-radeon-7970-installing-and-mining-in-windows-193695

Can you undervolt the memory as well? Maybe it is too hot.

I honestly think you'd be better off just running 4 cards in one rig, way more stable. Trying to push to the limit is fun but you soon get tired of constantly rebooting your rig etc. I like sleeping well and not worrying if it crashed 3 minutes after I went to bed 

What motherboard are you using?

I run Windows 8 w/ 13.1 & 2.8

Im running a Lepa G1600 and working on trying to get 5 - 7950s working, up to 4 ATM, on it

Need as much feedback and advice as I can get!!

I'm trying to get a x6 7950 up and running smoothly. I've been doing some preliminary testing on different, OS's, tried, BAMT, CentOS, Xubuntu, Ubuntu, Windows, I've cycled through all of these a million times. Originally I had a 850w corsair and 600w corsair, but that was a no go. Tried a 1000w corsair and 600w corsair still no go, tomorrow I give it a run with a 1600w Lepa, that'll solve my power promblems hopefully.

I'm running MSI 7950's the R7950 TWIN FROZR 3GD5/OC to be specific. Now with this card under volted at 1.087 and many other settings in cgminer, I can easily hit 680, with close to 12% reject shares in Windows. In Xubuntu it was about 615 12% stale, in Ubuntu with a higher clock/memory about 650, with again 12% stale, and so this was just testing one card, but as soon as I plugged in a second or third card Windows would lock up with driver issues. Ubuntu/Xubuntu would have power issues. (with the 1000w) with the 850w I could see two fine in any OS, and could mine with both pulling 680 with 12% reject shares.

I was using 12.7, 12.8, 13.1 drivers, tried all three, 13.1 seems to be doing good right now. And for the SDK 2.8

Now for the issue of PCIe slots, all three of my 16x slots handle non powered and powered extenders fine. my 1x slots one and two are good, but the third one I think might need a presence short, it was being picky. As far as powered extenders go, I was planning to do something like all the 16x powered(three) and 1x (three) non powered. This should be ok I think, or do pcie 1x pull less power through the board and would benefit more from a powered extender? And or should I just power extend all 6 of them?

As far as cooling goes, I can keep any card at 680 hashing constant, and keep the card below 65c with fans at under 60% (Not bad right?   ) So cooling isn't an issue. I have an open rig design, custom aluminum rig that I build, all the cards spaced out and bolted in and elevated. Excellent air flow/cooling etc. So heat from the GPU's isn't an issue.

Now do you think a 1600w 80 plus gold psu the Lepa one, that should be able to handle x6 cards just fine. What OS would you recommend for the best hashing? I really enjoy Xubuntu and Ubuntu, I just need to be sure to get up there with the hash rate and low rejected shares. I'm mining a lot of new little scrypt coins on small pools so I thought maybe it was the pool? I threw in some settings into cgminer, scan time, query, and one more I forgot, combined with a lower intensity of 18 opposed to 20, that were able to push the rejected shares  down to close to 5% however I was only mining at 650 (this is in windows)

So what are recommendations on OS, PSU, pcie slots/extenders, drivers?

Thanks,

Greg