I have a few rigs with 9GPU AMD 4GB and all of them have the same problem. Only 8 GPU's are working, GPU 1 hashrate is 0.0MHS and after some time miner restarts because GPU "is not working". Any tips for that error? Tried latest windows, different drivers....etc If I try to mine different coin they are all wrking at full speed, and no issue with GPU1....
You can also use integrated GPU if your CPU/Mobo supports it. Just connect hdmi to motherboard and check it out. Windows will use iGPU to display desktop and Phoenix will be able to use full GPU memory.