You could roll the dice on power constraints for the 6400 like the other poster noted.
Thing is you don’t need to go any higher because you’re bottlenecked by the cpu in addition to the psu, otherwise we’d recommend a 4060 or otherwise.
Amd vs nvidia-wise, you can run either chip, knowing that nvidia drivers may be a bit more of a struggle. I would consider ubuntu, pop, mint, etc in that case with steam starting in big picture, or even running windows with some registry tweaks so it still boots straight into big picture.
You could roll the dice on power constraints for the 6400 like the other poster noted. Thing is you don’t need to go any higher because you’re bottlenecked by the cpu in addition to the psu, otherwise we’d recommend a 4060 or otherwise.
Amd vs nvidia-wise, you can run either chip, knowing that nvidia drivers may be a bit more of a struggle. I would consider ubuntu, pop, mint, etc in that case with steam starting in big picture, or even running windows with some registry tweaks so it still boots straight into big picture.