I‘m having trouble with successfully mining Ethereum / Ethereum classic on a 4 GPU rigs consisting of:

1x Intel® Pentium® G4520, 1x Mushkin DIMM 4 GB DDR4-2133 1x GIGABYTE GA-Z170-Gaming K3-EU 4x Palit GeForce GTX 1060 DUAL 2x Kolink ZURC-007 Riser PCIe 1x Enermax Revolution X't II 750W 1x Intenso TOP SSD 128 GB

Running on Ubuntu 16.04 x64 with proprietary Nvidia driver 375.66.

Unfortunately one GPU connected over a riser is freezing all the time, sometimes after 3 h, 7 h, 20 h or even 5 min. I‘ve no idea what is happening. I swapped one GPU from a riser to the problematic slot (Riser energy, USB cable, Riser, PCIe bus, GPU energy) and the “replaced” GPU is freezing as well. I try to run 3 cards by using this slot and it hangs again. By using 3 cards without this “broken slot” it seems to work.

First I thought that I’ve an issue with the power supply but since a PSU calculator confirms that 750 Watt should be enough ( http://www.coolermaster.com/power-supply-calculator/ ) end Enermax guarantees 744 Watt over 12 V (even 850 Watt for seconds) I’m continuing my search. I measured 510 Watt at wall…

Under-clocking doesn’t helped so I’m running the cards on their default settings (except constantly 100 % fan speed). Temperatures are about 62-72° C all the time.

However I tried to use different programs for mining (ethminer, claymore) and I’m still having trouble with freezes. Claymore send “WATCHDOG: GPU 2 hangs in OpenCL call, exit” and ethminer just hangs up. Nvidia-smi doesn’t start up till a reboot.

Now I try to replace the “working” slot with the unstable components (~32 variations) in order to identify the problematic part. Due to the random freezes this could take 10 days or several weeks ( I’ve a job :-/ ).

Can someone help me? I appreciate any helpful suggestion!



2 Answers 2


The solution was to set the PCIe Port from version 3 to version 2 in the BIOS! Now it's stable for round about 14 days.


I solved the same issue by changing from Auto to Gen 1. It has to be changed in several places and all should match. After it's working I'd test your hash with each different generation to find what works best for you.

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