G'day!
I have several rigs mining altcoins 3 of them identical ASUS Z87-A mobo 3x Saphire 280X cards 1x-16 risers are powered the 16x -16x are unpowered PSU is 1200W bronze true.
Issue is they are all running nice and stable however cannot get the hash rate above approx 630Khs on any of the cards. The exact same cards on the exact same risers in an older Gigabyte mobo performing at around 730Khs or better stable and accurate.
Now I can only imagine this is a power delivery problem through the risers as if we plug the cards directly into the mobo they perform approx 25% better but still far from the other rig and optimal.
The 1x risers won't boot unpowered and the 16x riser won't boot powered.
Disabled power saving option and tried PCIE Gen1 - 2 and auto.
Strange thing is that there was also another gigabyte based rig that doing very well around 740Khs each cards and suddenly after a reboot it won't do more then 630 and 530 on the cards anymore.
What we have figured is if we lower the settings for the cards they actually perform a little better to a point but that's it nothing over 630Khs
What can it be? Driving me nuts.
Thank heaps/
Topic: Identical rigs produce different has rates and too low can't work out why (Read 466 times)
February 19, 2014, 06:41:07 AM
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