Need help whit encoding (Interframe parameters)

[Saimonmarley]

I use a apu cpu already using it at 99% whit x264 encoder and interframe fps adjust for 60fps but I want to use my gpu to speed things up I have a radeon rx 580 whit the latest driver I checked the gpu box on the interframe but still no gpu response on the encoding process. Have already tried on the misc-input to check the use gpu typing my device number (0)but still no responses. So how should I fix it. Should I change the encoder to a graphics card one? If yes how and which is the fastest one?