Same GPUs, different hashrate. Tried to switch risers, same result. Anybody?
Take a look at the fans right after it boots. I had a card that was not acting the same as the others in one of my rigs. After a lot of reboots and moving risers around i noticed a fan on one of the cards was acting differently than the others. Immediately after it powers up all of the fans are to spin at a fast rate and then stop. After another reboot i noticed one of them kept spinning for a longer period than the others. Eventually when it did stop it would still try to spin a little bit here and there. I replaced the USB cable and it has been running solid ever since.