The OG Steam Deck (7nm, comparable to the Series S) has a die size of ~162mm2. In there, it packs an 4 core, 8 threads CPU and a 8 CU GPU.
On the other hand, the Xbox Series S packs an 8 core 16 threads CPU with 20CU GPU of the same architecture in ~197mm2 die.
This is a technical question, how come the Series S packs much more in just 25% more size? I’m not saying the Steam Deck should be as powerful as a Series S (that’d never happen, the power constraints would not make it possible), but I wonder if the CPU in the Series S is cut-back or if there’s anything in the Steam Deck’s SoC that could have been removed to get a lower cost.
This is pretty much your answer right there. The Series S is a high throughput design, packed with shaders and CPU cores with relatively little cache per core but high bandwidth high power GDDR plus optimized software. Van Gogh is a low power design where the shader count is pretty much limited by the power envelope. A large part of the chip isn’t even shaders or CPU cors but other fixed function special purpose stuff. AMD could probably double Van Gogh’s throuput with +10% die space but that’s pointless because the power budget isn’t there.