sapphire 7970 4th card half the speed.. all cards slower

[makbot]

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!!

[1715136495]

1715136495

[firefop]

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.

[Charles999]

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.

[makbot]

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! 

[makbot]

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

[jayeeyee]

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.

[Charles999]

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

[makbot]

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+

[mrmanager]

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.