Does it not respect the -ethi argument? I run 2 on my main pc so i can barely tell it is running (Claymore). I can "feel" Phoenix running in the back ground at the same setting.
-ethi is supported and works roughly the same is in Claymore. You can try replacing
-ethi 0 with
-mi 0, which lowers the GPU load even more. The possible values of -mi (mining intensity) are from 0 to 12, where 10 is the default. Try the low values and see which one is best for your use case.