Nvidia practically owns the PC gaming market, especially the high end. Not sure how well PS games are running on PC in general, but if they aren't running up to snuff on Nvidia GPU's, then focusing on that would be a smart idea if PS is getting serious about entering the PC gaming market. The last thing PS would want to do is put their big guns on PC, only to have those PC gamers be let down by a sub par experience. First impressions mean a lot. Stadia, for example.
Then there's the long shot chance that a PS Portable is coming and it's got Nvidia hardware inside like Switch.
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