The Series S is basically an X with a weaker GPU

And significantly less RAM, which is probably the issue here.

The Series S is basically an X with a weaker GPU

If it was just a GPU difference, you’d be right it should be easy to just run it less pretty. But the memory limitations are the real issue. The X has 16 GB of memory and the S has 10 GB. And worse, the memory performance is drastically different. The X has 10 GB that runs at 560 GB/s and 6 that runs at 336 GB/s, where as the S has 8 GB at 224 GB/s and 2 GB at 56GB/s. (I did not miss a zero on the last value)

The main difficulty with split screen is that you need to be able to fit everything you need to render the scene into RAM, twice. Let’s go through some cases:

Just rendering to a higher resolution still lets you get away with the same amount of RAM if you use low-res textures, or a moderate increase because you’re using high-res textures, but only in the foreground – all you need is enough GPU compute power to push the pixels.

If you’re rendering VR both camera perspectives are going to be nearly identical, looking at the same objects, so RAM use is nearly identical to a single camera. Your frame time targets are much stricter in VR, you have to have high and very regular fps or people are going to puke, but again that’s compute pressure, not memory pressure.

In the split-screen case all bets are off: When players are at opposite sides of the map there may be literally zero meshes and textures in common between those two areas and you need twice the RAM for twice the amount of camera views. Nothing in common is the worst case, yes, but it’s bound to happen, and not leave PR in a situation where they have to say “We degraded performance when players are far apart to promote an atmosphere of closeness and cooperation”.

Split screen might be difficult for Series S due to memory constraints. Keep in mind that all assets both players are seeing must be loaded in memory simultaneously. This includes textures, models and animations. These assets are normally not loaded into the memory unless they’re visible by the camera. This becomes problematic if there are two cameras facing different parts of the map at the same time. Then you potentially need to double the memory requirements, which the Series S might not have.

did you think of the possibility that even Larian’s low settings still can’t run on series S? Given the amount of assets I saw it’s actually quite possible that vram requirement are pretty high and that’s why PS5 have delay as well so they can figure out ways to consolidate textures used etc. Like they can’t even manage to let me stack rope or water bottle properly in inventory(maybe some asset id not cleaned up during development), so having excessive vram usage is fairly easy/common for content heavy games.