I've now started mining with ethminer, however, even though it is correctly using my GPU (its usage is constantly at 100%), the program is also maxing out two of my four cores, to the point where their temperature is higher than the GPU's, I thought it was supposed not to use it, expecially because considering that using the CPU for mining is basically a waste of energy.

By the way, my graphics card is an NVIDIA gtx970 and my processor is an i7-4790k.

  • Did you find a solution to this? same problem with ethminer here. (same processor as yours) and 4 gtx1070, win10
    – Doug
    Commented Dec 13, 2017 at 22:59
  • 1
    @Doug yes I did, see my answer
    – Mauro F.
    Commented Dec 13, 2017 at 23:11

4 Answers 4


Ive noted this before when using Nvidia and the stock Ubuntu ppa ethminer. I switched to genoils and the problem was solved .. my CPU's mow run around 3 - 4 % while mining


I've eventually found a solution the problem was not ethminer, but rather geth that for some reason was mining using the CPU. To solve it's enough to run geth with the command

geth --minerthreads 0
  • Thanks but I didn't download and am not running geth? I just ran the ethminer itself, connected to a pool. Do I need to run geth on the background or something?
    – Doug
    Commented Dec 14, 2017 at 14:05

change -G to -U solved this for me.

-G,--opencl When mining use the GPU via OpenCL. -U,--cuda When mining use the GPU via CUDA.


In some cases (unfortunately many), the processors in Windows 10 show 100% usage. From what I understand the problem grows according to the number of GPUs. Windows 10 overloads processors that have few flames when GPUs are more than the threads.

I found some tweaks for windows 10 and achieve more than 50% less CPU usage.

New CPU Usage: 45%


Just let me know about your results.

Have a nice mining!

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