Xbox Series X will average 4.8GB/s in realistic data transfer of typical game data.
Its best case unrealistic scenario where it's only streaming an exceptionally compressible texture file will be somewhat higher, and I've seen 6 GB/s mentioned typically.
The elements that make up their streaming architecture (2.4GB/s SSD, BCPack decompression block, Sampler Feedback for Streaming filters, DirectStorage) aren't arbitrarily added onto those numbers. They result in those numbers when real world performance is measured.
PS5 will average 8-9GB/s in realistic data transfer of typical game data.
Its best case unrealistic scenario where it's only streaming an exceptionally compressible texture file will be higher at 22 GB/s.
The elements that make up their streaming architecture (5.5GB/s SSD, 6-LoP 12-Ch controller, Kraken decompression block, DMAC, IO coprocessor, memory mapping coprocessor, SRAM, Coherency Engine, GPU cache scrubbers, ID based storage API) aren't arbitrarily added onto those numbers. They result in those numbers when real world performance is measured.