Quoting my previous post lol... Check out the first image. You really need to get them out of the case and into the open air. Particularly if the room they are in is not temperature controlled, i.e aircon and ambient temp in room is a little on the warm side... Just get yourself an el-cheapo shelf (mine in the image cost me 15 bux! from a bunnings/home depo type hardware store), some x1 or x16 risers and suspend those puppies above the board. The fan you see in the image is from a decommissioned Xigmatex CPU cooler. It feels like my 50w floor fan/box fan it pumps that much air but not nearly drawing as much power. I used to use the floor fan/box fan to cool these babies down when they were in my case, which was a Sharkoon T9 Value case on it's side with the side off and temps were what you're reporting atm (80ish-90C). The rack they're sitting on is just from an old fridge we have in the garage that does not work anymore, so I salvaged one of the racks from it and use that along with a couple of pieces of dowel to rest them on.

I tried to avoid all this shit to keep temps down but I had to bite the bullet and get enough air flow through them, especially since I wanted a constant 750+kh/s without the risk of cooking the cards. It paid off in the end. The biggest hurdle was attaining the risers... I had them on order already but couldn't wait for stock to arrive so I managed to get some sent locally aswell and was back up and running in a couple of days.

With the F62 bios already on my cards, my GPU/Memclocks are 1100/1500 and that's what I mine with. Any more or less on either GPU or Memclock and my hashrate drops significantly, like ~100kh/s drop! Currently they're both hovering a little over 770kh/s and temps are 70C/62C respectively as I type this. Rock solid for days now no issues with screen freeze or anything. Open rig was the key for me to keep the temps down.. well that and risers to get more air flowing around them both. Very pleased with the outcome considering the top card (when they were in a pc case on it's side and case open) was hitting above 100C easily while the bottom card was climbing slowly above 90C. These temps were unacceptable and I did not mine untill I had them in their current setup. Even when they hit 80C on a hot day (it's rather chilly outside atm so room is a few deg above that) I still cringe and worry about them while I'm at work. But I remote monitor their progress and so far so good... fingers crossed

I have 2 x Gigabyte 7970 Ghz Editions 1100/1500. These cards demand excellent airflow otherwise you'll have stupid temps as did I in the beginning 99C+ !!! They're a great card and clock very well despite being voltage locked :\

My setup: http://imgur.com/eWclj9s

My stats: http://imgur.com/ceKzyov

Hosted on my own personal domain: http://www.showed.us/crypto/Underclock.zip

Donations are welcomed!

Just an update, got the two x16 risers I ordered last week in the main today and am very happy they got here rather quickly too. Can now hook up some more gfx cards to my rig. So thank you for the speedy delivery, canucks + hashratestore ftw!!

The voltage lock shouldn't be an issue mine are locked and I still got them hashing over 700Kh/s. Infact, they're doing 770Kh/s each atm and sitting between 65-75C. It was a pain in the arse to get them to play nice but persistence is the key to virtue - also an open rig setup for proper cooling and the right command line helped massively. See below for imagery!

Sexy Image of Rig

Miner Monitor Stats


Awesome stuff mate, stoked you got there in the end haha you see, no need to have 346423874623 options on CGMiner startup. A simple clean command line and the help of a BIOS flash coupled with latest drivers (bleeding edge too!) got you there in the end. Beta drivers ftw!! Just curiously what was the temp before the screen went black? It probably shut down cause it overheated I'm thinking. They really do run rather hot and require decent cooling to keep them stable and free from burning out. Those pesky VRM's have piss poor cooling on their own and I had to move the entire setup out from an open case onto a rack with adequate spacing just to keep the temps down :\

Really happy you got things going in the end

Good stuff, glad you got an improvement through flashing looks like there's still hope for the card yet! If you're hitting 590Kh/s then realistically 600+ isn't that far off. It's a matter of just tweaking now and finding the right driver. I'm using Windows 7 Ultimate and Catalyst 13.6 beta2 drivers on my rig and one of the cards has a dummy plug I made with a few resistors. Despite the fact recent versions of catalyst dictate you no longer need a dummy plug, I find I still have to use one otherwise I'll either get a series of ADL/OpenCL errors and/or one of the cards will hash stupidly low. Like in the 30Kh/s-70Kh/s range :\

Also, why are people using both --shaders and --thread-concurrency together.. the latter overrides any value set by the former so it's kinda pointless.. as is lookup-gap since it's already set at a default of 2 anyway. I had so much trouble fiddling with settings wondering why my cards weren't hashing as everyone else's or even remotely close. Point being, 700+Kh/s should be easy to attain with minimal input parameters unless ofcourse the card really is defective or just plain shit 

I'm sorry you're having such difficulty with these cards. I'd probably stick to 1500 mem as MSI Afterburner is showing me very little memory usage while scrypt mining, seems rather odd but I can live with that. I saw no hashrate difference when adjusting the mem except for the card crashing past 1800 mem so I left it at it's stock. It's certainly helped with keeping the silly VRM's temp down thats for sure... Give the beta2 drivers a shot they won't hurt the card might actually give you a small increase. Then again, it might not but it's nice to rule out that version nonetheless...

Just be sure to use the amd driver cleanup utility when changing drivers. You don't want any remnants of previous drivers screwing with your results, that and amd overdrive = off. Other than that I really don't know what else to say. This card is being stubborn 

FWIW, Win7 64bit, 13.6 beta2 drivers here CGminer 3.2.1. 2 x Gigabyte 7970 GHz Editions (voltage locked). Hashing ~769Kh/s on stock 1100/1500 clocks. I have them on powered risers now but before that they were doing ~734Kh/s with 1045/1500 clocks, anymore or less on the core clock would see the hash rate drop sharply both with or without risers. Same deal with memory increase/decrease... Setting intensity to anything other than 13 would also drop hash rate sharply. Using --shaders instead of --thread-concurrency also dropped hash rate sharply as did using -g 1. Side note, despite setting --thread-concurrency to what cgminer detected originally (22400) it too resulted in a massive hashrate drop.

Without risers - Catalyst 12.6 beta, 13.4, 13.6 beta drivers ~734Kh/s

With risers - Catalyst 13.6 beta, 13.6 beta2 drivers ~769Kh/s

You can view my "before risers, driver/cgminer upgrade, remove rig from open case and put on shelf" stats Here.

As mentioned earlier, you really do need to just 'fudge' with it as it's all trial and error... I also read it's a good idea to delete the .bin files in the cgminer folder when adjusting settings on the command line. I found 50% of the time this would solve any issues I might have had tho the other 50% of the time I saw no change in my issues. The biggest change I saw was going from 13.6 beta to 13.6 beta2 drivers, an increase of ~30Kh/s although I'm unsure if this was due to the driver upgrade since I did so when I installed the cards on their risers. To achieve these results I cleared the .bin files, turned off AMD Overdrive in catalyst and just ran cgminer.exe -I 13. Let it decide what to use and go from there increasing/decreasing clocks and/or intensity within the running app. You'll hit a sweet spot eventually, or be like me, try the same settings over and over then one day like pure voodoo magic those same settings work a treat when previously they made things worse

Don't flash your bios, you shouldn't really need to and I considered going down that route after pulling my hair out trying to get these darn things to play nice... If you do flash, make sure you backup your original bios. ALWAYS BACKUP...just incase...

I guess it's a trial and error thing really, try with just the 7950 and tweak it till you get it hashing right. Try with just 8192 thread concurrency. Lower clocks seem to yield better results than higher ones. Although this is going by experience with my 7970's... BTC mining is obv different.

Start cgminer with just the -I 13 (add --thread-concurrency 8192 if you want lower TC to begin with) and play with the core clock. There will be a sweet spot either with the core or memory clocks. Originally the clocks I'm using now, my cards didn't like at all... dunno what happened but after a few reboots the same clocks I'm using seemed to work a treat. Any more and hashing would slow to a crawl. Unfortunately each card is different but you'll find a decent hash rate eventually.. Really that's all I can offer in advice, which seems a little bland and kind of an empty response but given that I don't own a 7950, I can't really say what will work well with your card. There are a fair few threads on those cards tho, I found myself trawling through a tonne for my 7970's... alot of the settings suggested didn't work for me but a combination of a few helped me get on the right track.

You're deleting the .bin files between settings changes? I read it's a good idea to do so when adjusting cmd line parameters for cgminer.

Edit: I found when using a high thread concurrency, cgminer would either shit pants or my 7970's would hash stupidly low. Like 100-300Kh/s each, despite cgminer detecting 22400 for TC.

I mine LTC atm and both my Gigabyte 7970 Ghz Edition cards do ~730Kh/s. On stock 1100/1500 clocks they only manage ~560Kh/s but if I drop the core clock down a notch they ramp up and mine away happily. Sadly they are voltage locked so there is not much at all I can do about that

Link to screenshot

CGMiner settings in my batch file are:

Yeah the one time I decide not to go brand name and it bites me hard in the arse!  Never again thats for sure...

I'm quite pleased with the PSU, it definitely is a beast and hasn't skipped a beat. Really stoked things turned out for the better even if it did take almost frying everything in the system for me to understand the importance of a quality PSU!

Just waiting on some risers to arrive now so I can hook up the 2nd 7970... I get some stupid temperature issues when both are plugged in with whichever one is in the top slot rocketing to above 99C. I'm hashing away with just one of them for the moment and on a warm day it doesn't go past 75C. Mostly stays between 59C-65C and getting 734KH/s mining LTC, haven't tweaked around with BTC since before I blew the other PSU... None the less, everything turned out for the better and at least the power issue is now gone for good

If you go here https://bitcointalk.org/index.php?topic=28402.0, you'll find what you're looking for. Also here https://github.com/ckolivas/cgminer/blob/master/README which is pretty much the same thing. Just scroll down a little on the first post in the first link to get the definitions of the UI.

I would say they are 19cm? long... I read somewhere that anything greater than 30cm's for a riser cable would cause problems with the card. Infact there is another thread on here that talks about this. Someone is offering to sell 30cm riser cables and was asking if there is any interest. Here is the link to the discussion... Clicky!

It was this one that I bought and it blew on me.. but the nice guys at itestate exchanged it for me tho I opted for an upgrade and went for the Silverstone Strider Gold 1200w. Been running great guns with both my cards and no issues at all. I'm looking at a kill-a-watt solution so I can get a reading from the wall on how much power I'm really drawing and will endeavour do obtain one from JayCar this weekend when I have time. They sell an equivalent for around 20 bucks which is not too heavy on the hip pocket money wise

All in all, I learnt a lesson from trying to be cheap (unintentionally) and as a result almost lost more in hardware which would have really been a hard kick to the balls.

Mine are voltage locked so I'm up shit creek in a manner of speaking. In saying that, I CBF reflashing to a different bios and seeing as having one card in at a time doesn't go past 70C, I'm keeping fingers crossed that these risers will help me out somewhat in spacing the cards out more and allowing more air to flow around them. Had a constant temp of 65C last night given it was a rather cold evening and the lowest I got was 59C...

These are the Ghz editions non reference I might add.

Edit: Argh didn't read you stated 7950, thought it was 7970 - My bad

2x7970's in an open case 4x120mm fans blowing straight on them and card fans @ 85%. When sandwiched together, whichever card I have in the top slot rockets to 100C easily and would keep on rising if I didn't stop cgminer. The bottom card in this configuration only gets to about 75C. On their own they comfortably sit between 60-65C, so I'm waiting on powered risers to arrive so I can hash with both the cards again instead of just the one. This should hopefully solve my cooling issue or at least stop the insanely high temps.

0.2 

This looks promising so I ordered 2 x16 risers (Order #1109). BTC Sent and Confirmed (atleast from my end)... Curious to try these out and the bonus, quite a bit cheaper than other webstores I've visited. Nice and simple store layout too so props on that