unfortunately, radontop doesn’t support relatively old cards. I get this error. (And the github page states that >R600 will work)

Unknown Radeon card. <= R500 won't work, new cards might.

Also, my AMD CPU has a integrated GPU too, radeontop just doesn’t know about it.

The GPU works on my system tho, just radeontop doesn’t detect/support them. Oh well.

Can’t go wrong with Debian and some ligthweight desktop environment, like xfce, as someone also mentioned here