According to Digital Foundry’s John Linneman, Xbox Series S will not be able to support Xbox One X’s enhancements for Xbox One games.
Linneman claims that Series S’s GPU is capable to handle the task of backward-compatible games, however, due to its RAM limitations, the console will run older games on One S mode. The 8GB GDDR6 224GB/s RAM is one of the compromises made by Xbox’s designers to create a product that is capable of running next-gen games at a bargain price.
It may be running backwards compatible games in Xbox One S mode, but because the GPU is so much more capable, and knowing what we know about how backwards compatibility works, you should actually still be able to clean up performance issues,” Linneman said.
So games that maybe struggled on Xbox One S, either the dynamic resolution was overly-aggressive, with slowdown and things like that, conceivably they could actually run noticeably smoother on this machine.
Official information from Xbox claims that Series S is significantly faster than the previous-gen Xbox.
“Xbox Series S also delivers approximately 3x the GPU performance of Xbox One and was designed to play games at 1440p at 60 frames per second, with support for up to 120fps.” Said
Another limitation of the Series S lies in the limited 512GB PCIe Gen 4 NVMe SSD and the lack of a disc drive. In the long run, Xbox Series S owners will need to buy the expansion card offered by Xbox that doesn’t seem to be cheap.
The NVMe drive is designed by Seagate. This device will allow players to save and run Series X games directly from that expansion port. players will also have the ability to use standard USB SSDs as a storage expansion device, the only caveat is that next-games can only be played through the official Seagate expansion card.