Please note that this post is tagged as a rumor.
AMD Navi 4C: The GPU that will never be?
This would have been the AMD flagship RX 8000 GPU if not for the fact that it was canceled, allegedly.
Moore’s Law is Dead recently shared a diagram of AMD’s unreleased RX 8000 GPU, codenamed Navi 4C. In AMD’s plans for their next-gen series, they were initially preparing four GPUs, but Navi 41 and 42 were allegedly canceled.
The leaked diagram showcases a large package substrate that accommodates four dies: three AIDs (Active Interposer Dies) and one MID (Multimedia and I/O die). It appears that each AID would house as many as 3 SEDs (Shader Engine Dies). This complex configuration represents the alleged RDNA4 architecture, or at least a segment of the GPU that was intended for future release. Notably, the diagram only presents one side of the design, omitting the complete picture. MLID notes that there should also be memory controller dies on each side, although their exact number remains unknown.
The proposed Navi 4C GPU would have incorporated 13 to 20 chiplets, marking a substantial increase in complexity compared to RDNA3 multi-die designs such as Navi 31 or the upcoming Navi 32. Interestingly, a similar design was identified in a patent titled “Die stacking for modular parallel processors” discovered by a subscriber of MLID, which showcased ‘Virtual Compute Die’ interconnected through a Bridge Chip.
It’s important to note that Kepler_L2 was the first to mention Navi 4C, along with references to Navi 4X and Navi 4M designs. However, no leaks about the latter two have emerged. The relationship between the C/M/X naming convention and Navi 41/42 remains unclear.
This leak confirms that AMD’s Navi 4 project is a substantial endeavor. The complex nature of this design could have posed challenges for the company, leading them to opt for established and proven GPU layouts. How will this affect Radeon RX 8000 series as a whole is yet to be determined.
Few more codenames 🙂
— Kepler (@Kepler_L2) April 18, 2023
The Navi 4C design diagram was shared during Broken Silicon podcast, we timestamped the video.