Bitcoin Forum

I recently built a rig and have an asrock z4 mobo and qty 4 7970 gpus.  newb to all this and first build.

i had only 2 installed originally and they ran between 580-650 mh/s.  is it normal for the cards to vary so much from minute to minute?

also when i put in my 4th card it's hash rate barely hits 300 mh/s.  i'm using bitminter and thought about trying another miner, but being a newb i wasn't sure if that would have a large impact.  

help is appreciated.  i searched quite a bit but did not really find much regarding a 4th card or variable speeds when mining.

thx!!

If these are mounted directly to motherboard - it's most likely a heat issue of some sort - get those thing on extenders (which molex power) for better ventilation.

Mine too.  But I only have 3 cards!  I hope someone pops up an answer.

i figured out part of my problem.  i have all my cards on powered pcie extensions and the male end of the power connector would pop out when plugging it into the power supply connection.  this would cause a loose connection.  assuming this was causing a bad power connection and making my rig act inconsistent.  now all 4 cards are running at similar speeds.  around 550 mh/s.

i still get some fluctuation with the hash rates, but not nearly as bad.

now i just need to get a config that gets me closer to 650-700 per.  i have a 1250watt ps so that shouldn't be a problem.

if you dont have powered pcie extensions/risers then that will absolutely cause a problem.   i found some people wondering if they need them.  yes you do for these cards.  i found that cablesaurus has the 16x to 16x risers.  not quite sure why they are so hard to find.

anyways.. just like any troubleshooting... check all your connections! 

oh ya.. all my cards run about 66 degrees Celsius.

I've had similar issues.  I run my miners remotely.  However, if I have to restart it, I will need to turn on the monitor or else the card connected to the monitor will hash at 1/2 the speed it's capable of.  The reason for this? No clue.. but turning it on and then running w/e miner software will remedy this.  After that, I can turn the monitor off and start hashing away as normal.  I don't know if this might fix your issue but I'd thought it's still worth 0.000001BTC to someone else of similar issues.

That's really wierd.  I will have to check that out.  I run mine remotely too.

How do you adjust clock speed etc..remotely?  Afterburner doesn't show up right.  Can't adjust remotely

i cant even remote into my pc when its mining.  monitor is only way.  but i dont see much prob with that.  i guess i can consider this one solved.

now to find a good config.  i dont seem to get the same results as others do.. would love to get the cards all running at 650+

Try using cgminer with the diablo kernel and a 128 worksize. You also need to adjust the intensity. I'm at 11 for both of the cards below. My Sapphire card has been stable for 6 days now.

I have a Sapphire 7970 averaging 708 MH/s with the core clock at 1175 and memory at 250, and a Diamond 7970 averaging 689 MH/s (1145/350). If you're using Windows, you can also use cgwatcher. cgwatcher will restart cgminer if your drivers crash. Both cards run anywhere from 62-69 degrees Celsius. I have the case open and a small fan blowing on the cards.

To remotely manage your rig try Chrome remote desktop, or something like Team Viewer. Team Viewer works very well with my Nexus 4.