Hashrate dropped on my 6950's - Wondering why

[nodesupply]

I'm using GUIMiner + scrypt to mine LTC and I've noticed my hash rate dropped about 1/5 (from 500 khash to 400) on two cards in one of my rigs.
I'm wondering why this was the case.

The cards run really hot, and I'm wondering if it could be because I handled them right after powering the machine down and not giving them enough time to cool off? This may sound silly but I really can't think of any other reason.

All I did was power down the machine, pull a card out (it's a caseless rig, just a motherboard sitting on a plastic shelf) and replace it afterwards.

The heatpipes were very hot. In retrospect I should have waited but I was impatient to test another card I had just gotten.

I'm wondering if anyone has any ideas.. Thanks

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[Gator-hex]

Heat pipes should be hot, that's their purpose to move heat away from the chip, what temperature is the card reporting?

I sometimes wonder if people will write code to steal a fraction of someone's hashing power.  

You can break a card by not letting it go through it's cooling cycle but it would probably be totally dead.

Check you have crossfire disabled sometimes this slows a card down.

[d4rkbreaker]

I'm using GUIMiner + scrypt to mine LTC and I've noticed my hash rate dropped about 1/5 (from 500 khash to 400) on two cards in one of my rigs.
I'm wondering why this was the case.

The cards run really hot, and I'm wondering if it could be because I handled them right after powering the machine down and not giving them enough time to cool off? This may sound silly but I really can't think of any other reason.

All I did was power down the machine, pull a card out (it's a caseless rig, just a motherboard sitting on a plastic shelf) and replace it afterwards.

The heatpipes were very hot. In retrospect I should have waited but I was impatient to test another card I had just gotten.

I'm wondering if anyone has any ideas.. Thanks

Try running the GPU again with 70+ % fan speed, don't overclock now and test for consistent hash rates. Overclocking your GPU blindly while leaving the GPU at 90C+ is asking your GPU to die. If you have no idea how to control the fan, use MSI Afterburner or Sapphire Trixx to manual change the fan speed.