HI Dyetox, I use the Graka in combination with an i9-9900k and 650W is perfectly sufficient for me. But I don't overclock at the moment. I recommend using the following power supply calculator: https://www.bequiet.com/en...

It depends. Do you want to overclock the card? If you plan to flash the 380W BIOS on it and have overclocked a power-hungry CPU to the maximum, I would recommend at least 850W. I have a very high quality, used 1200W platinum silent power supply from Kolink if you are interested.