You could do this today already, just need to be able to fit it in the chassi. You can power the GPU with a different power supply than the one supplying the re

You could do this today already, just need to be able to fit it in the chassi. You can power the GPU with a different power supply than the one supplying the rest of the system. Cryptocurrency mining setups does this frequently, so there is lots of prior art around for doing just that.