Both nvidia and amd dont have official support for dayz because you know what? Dayz doesnt support mgpu correctly atm. So dont expect +90% gpus usage.For nvidia you use nvidia inspector for amd you force Arma2 or 3 profile. Its a common solution for years.I dont know if you use first time mgpu but this is common. So deal with it or go back to 1 gpu. Titanfall either force 1x1 or afr friendly.