I have 3 rx 480 and 1 gtx 980 (total 4 Cards) I can not run the gnoil because always detect the NVIDIA, although I run the CUDA version or OpenCL always detects me 1 card (the GTX 980) what is the problem?
You can try running to instances, one with 1x CUDA and other with 3x OpenCL where you define the cards to be used, use
ethminer --list-devices -G
to see the numbers for devices and then use --opencl-devices and --cuda-devices.