GPUs and Mercury playback in Premiere 2017 Mac OS X Sierra and older Macbook Pros

Hi. I'm considering to buy a second hand Macbook Pro with an nVidia 650 with 1 GB (I think actual prizes on new Macbooks are overvarrated considering performance), but I'm not getting clear information if it's possible to make this card running Mercury Playback with this version of Premiere Pro. I apologize if this has been answered, I've taken a look but I couldn't find.

Another thing: if someone has had the option to test both: AMD or nVidia with Premiere Pro 2017?

Thanks.