An independent chip expert has managed to examine die shots of system-on-chips that power the latest game consoles from Microsoft Corp. and Sony Computer Entertainment Division. The SoCs resemble each other in many ways since they share architectures as well as are made using the same process technology. Nonetheless, the dieshots prove that the processors are different.
Chipworks, an independent chip analytics company, has dissolved packaging of Microsoft Xbox One and Sony PlayStation 4 and managed to make two high-quality die shots of the chips under a microscope. The chips are identical in die size: the PS4 SoC is 348mm2, whereas the X1 SoC is 363mm2. Given similarities in clock-rates of the hybrid processors, they should have identical power consumption as well.
The die shots reveal two quad-core Jaguar x86 modules with some shared elements within the each SoC. It is hard to estimate whether Microsoft and Sony altered those modules architecturally or not, but in general the quad-core modules look similar.
As expected, the chips have different amounts of AMD Radeon GCN [graphics core next] compute units: the Xbox One SoC features 14 CUs (with 64 stream processors per unit), two of which are reserved for redundancy; the PlayStation 4 SoC sports 20 CUs (with 64 stream processors per unit), two of which are also reserved for redundancy.
Despite of having considerably lower amount of stream processors for graphics, physics and other highly-parallel computations, the Xbox One SoC features 32MB of SRAM cache for graphics + 15MB other caches, which takes a lot of chip space. Therefore, the cost of X1 and PS4 SoCs should be similar. It is also noteworthy that Sony PS4 SoC has more complex, distributed GDDR5 memory controller, whereas Microsoft X1 SoC features less complex distributed multi-channel DDR3 memory controller.
Both system-on-chips have massive uncore space, which suggests that there are lot of proprietary logic and interfaces inside all designed to boost overall compute performance and provide simplified access to that performance by game developers.
The first analysis of very similar chips shows that Sony PlayStation 4 has a higher-performing system-on-chip under the hood. However, the analysis does not exactly reveal all the secret sauces that Microsoft might have put into the Xbox One SoC.