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.