I'd love for someone in the know to give a definitive view on this. I mean, as a layman, I can't see any logical reason why it would impact performance any more than the 4K (or whatever) version, so presumably it's down to changing some settings. But I'm not a dev, so maybe it is a lot harder than I imagine. That the X1X will do it at a system level suggests it's not too difficult, tho.Apparently it's not, given the amount of games that don't support it (although it's worth noting that most games that have PRO support do offer Downsampling).