Xbox One APU reverse engineered, reveals SRAM as the reason for small GPU

For months, Sony and Microsoft fanboys have lined up to hurl insults at each other over which console would pack more hardware, hit higher performance targets, or prove a better design for the next generation. With the two consoles launched, the game-to-game comparisons have mostly come out a wash, with a slight edge for the PS4. But there’ve still been questions about the underlying chip design — which architecture is more efficient, and what unique sauce went into each console?

The fine folks at Chipworks have completed their teardown of the Xbox One and given us an answer to that question — and a few puzzles to go with it.

The Xbox One die is 363 square millimeters, up from the PS4′s 348 sq mm. The 5% additional space, despite having the smaller GPU core, is mostly due to RAM. The Xbox One contains a whopping 47MB of on-die RAM, and that pushes the die size up considerably. It’s also why Microsoft didn’t have room on the APU for a larger GPU.