Unknown OpenCL driver version! Hashrate and stale shares may suffer
OpenCL platform: OpenCL 2.1 AMD-APP (2766.4)
Available GPUs for mining:
GPU1: AMD Radeon (TM) RX 480 Graphics (pcie 1), OpenCL 1.2, 3.2 GB VRAM, 36 CUs
GPU2: AMD Radeon (TM) RX 480 Graphics (pcie 3), OpenCL 1.2, 7.9 GB VRAM, 36 CUs
GPU3: Radeon RX 580 Series (pcie 4), OpenCL 1.2, 8 GB VRAM, 36 CUs
GPU4: Radeon RX 580 Series (pcie 6), OpenCL 1.2, 8 GB VRAM, 36 CUs
GPU5: Radeon RX 580 Series (pcie , OpenCL 1.2, 8 GB VRAM, 36 CUs

im on ubuntu. i wonder witch is the know opencl driver ?