Driver leaked AMD Navi 31 has 6 MCDs

AMD and NVIDIA’s next-generation graphics cards are in orderly and steady progress. Although the possibility of seeing AMD’s new generation of graphics cards within this year is not very high, even if it can be seen, it will be the end of the year, but various news will gradually flow out. Now someone has found clues about the RDNA 3 architecture graphics card in the Linux-driven code.

According to videocardz, MCD_INSTANCE_NUM is listed in an AMDGPU Linux driver, which is the assumed memory of the RDNA 3 Navi 31 GPU that matches the number of it/controller chips. Interestingly AMD replaced MCD with UMC_NODE after a week, apparently to hide the secret.

This roughly confirms the rumors that the AMD Navi 31 GPU has one GCD (Graphics Computing Chip) and 6 MCD (Multi-Cache I/O Chips). The card is likely to have 384-bit video memory, and possibly 192MB of Infinity Cache, which would increase to 384MB if AMD used 3D V-Cache on every MCD. In fact, in May this year, the design block diagram of Navi 31 GPU flowed out. From the picture, it can be seen that this GPU is quite large, but the specific size is not clear.

With 384bit video memory width and 18Gbps GDDR6 video memory, the memory bandwidth of the new flagship Radeon RX 7900 series graphics card can reach 864GB/s, which is 50% higher than that of the RX 6950XT. This value does not include the bandwidth of the Infinity Cache, which is 50% larger than the current Navi 21.