Rumored AMD RDNA4 Silicon Design Reveals Highly Complex Chiplet Layout
Rumored AMD RDNA4 Silicon Design Reveals Highly Complex Chiplet Layout
Image: creper9000
AMD’s upcoming RDNA4 GPU is seemingly off to a rocky start, as rumors are claiming that Team Red is ditching its efforts to compete at the high-end GPU market, potentially leaving NVIDIA unchallenged in the upcoming generation. Various leaks on RDNA4 has been uncovered over time, and the recurring theme seems to be on the extremely complicated multi-chip design that far exceeded current chip designs.
Image: Moore’s Law Is Dead
The chip in question is dubbed “Navi 4C”, first leaked by Moore’s Law Is Dead. This silicon houses as much as four base dies: three Active Interposer Dies (AIDs), one Multimedia and I/O Die (MID); and under each AIDs are up to three Shader Engine Dies (SEDs). There’s also the memory controller dies, allegedly, that should be situated on each side, making this a highly complex layout to build at scale. It’s somewhat relatable to Intel’s “Ponte Vecchio” server GPU – now called Data Center GPU Max series – which contains a massive number of chiplets. 63 of them, in fact.
Part of that complexity comes from the fact that it will be a stacked chip, which – when combined, may consist somewhere in between 13 to 20 chiplets. (RDNA3 silicon only has 7 at most, split between a single GCD and 6x MCDs.) This isn’t the full story of Navi 40, however: leaker @Kepler_L2 has claimed that three types of RDNA4 silicon exist – Navi 4C, Navi 4M and Navi 4X. The exact nature of each variants are not known at this point.
Image: Olrak29
Leaker Everest (@Olrak29) has revealed a diagram on Navi 4C’s chiplet layout, which is based on the diagram published by MLID above. @creper9000 has created a visual render of how it’d look like on a silicon, and it’s quite unlike any GPUs seen before – short for Intel’s massive Xe-HPC-based Ponte Vecchio chip.
Image: creper9000
With doubts casting over RDNA4’s eventual fate, it’s also not known if AMD has opted to push these packaging technologies further down to RDNA5 or even further generations. For now though, Team Red still has its “Enthusiast” class GPUs to deal with first, set to be announced in Gamescom next week.
Pokdepinion: With no word on NVIDIA’s progress when it comes to multi-chip packaging, it’s safe to assume AMD is well ahead in the chiplet tech; however for something as intricate as Navi 4C it’s definitely difficult to manufacture at scale with the complexity at hand.
