Error: "No usable mining devices" despite benchmark is ok

Question

I am new here, and this is my first question.

I have just installed ethminer on ubuntu 20.04 and it seems that everything is ok in the settings:

1. The command ethminer --list-devices gives

ethminer 0.19.0-17+commit.ce52c740
Build: linux/release/gnu

 Id Pci Id    Type Name                          CUDA SM   Total Memory 
--- --------- ---- ----------------------------- ---- ---  ------------ 
  0 03:00.0   Gpu  GeForce GTX 1070              Yes  6.1       7.37 GB 

2. Running a benchmark with the commad ethminer -G -M 0 works well

3. Moreover clinfo gives the following

Number of platforms                               1
  Platform Name                                   NVIDIA CUDA
  Platform Vendor                                 NVIDIA Corporation
  Platform Version                                OpenCL 1.2 CUDA 11.2.109
  Platform Profile                                FULL_PROFILE

Nevertheless when I try to really run ethminer by typing for example:

ethminer -G --report-hr -P stratum1+tcp://XXXXXXXXXXXXXXXXXX.@eth-eu1.nanopool.org:9999

then I get:

ethminer 0.19.0-17+commit.ce52c740
Build: linux/release/gnu

Error: No usable mining devices found

Do you have any idea on what is happening here?

Answer 1

Change -G for -U. This worked for me.