AMD's high-end Navi 4X GPUs featuring the RDNA 4 graphics architecture were reportedly going to feature 50% more shader engines than Navi 31 "RDNA 3" chips.
AMD's Cancelled RDNA 4 "Navi 4X" GPUs Would Have Featured 50% More Shader Engines Than RDNA 4 "Navi 31" Chips
New patches regarding AMD's GFX12, spotted by Kepler_L2, seem to point out some significant upgrades on what could've been a true successor to AMD's flagship RDNA 3 GPU called Navi 31.
According to the patches, AMD's GFX12 family which is the codename for the RDNA 4 GPU lineup was reportedly going to feature up to 9 Shader Engines on the top Navi 4X or Navi 4C SKU. These GPUs would have marked a 50% uplift in shader engines count over the Navi 31 chip which comes with 6 Shader Engines.
AMD made two split configurations within its RDNA 3 GPU lineup with Navi 31 featuring a total of 16 compute units (Dual Compute Units per WGP) per Shader Engine for a total of 96 compute units while the Navi 32 GPUs offered a total of 20 compute units (Dual Compute Units per WGP) per Shader Engine for a total of 64 compute units.
Now it is not known if RDNA 4 would have followed the same Shader Engine configuration as Navi 31, Navi 32 or gone a completely different route but it is reported by Anandtech Forum member, Adroc_Thurston, that the actual compute units were over 200 for the top Navi 4 "RDNA 4" GPU die.
The GPU was meant to feature 3 GCDs, each with 3 Shader Engines, marking a true shift to chiplets for consumer-grade gaming GPUs. Following is what the configurations would have been using Navi 31 and Navi 32 designs:
- Navi 41 with Navi 31 configuration: 9 Shader Engines, 16 Compute Units, 144 CUs
- Navi 41 with Navi 32 configuration: 9 Shader Engines, 20 Compute Units, 180 CUs
- Navi 41 with 200+ Compute Units: 9 Shader Engines, 24 Compute Units?, 216 CUs?
These are just theoretical configurations that can come up with but if true, then it looks like AMD was working on a high-end chip that could have offered real enthusiast-grade performance and capabilities, but it looks like the red team canned plans for such a design due to reasons which we may never know. It could be due to design complications, yields, or even cost but we can't say for sure.
Renders based on the rumored die configuration of the Navi 4X (Navi 4C) chiplet GPU were also showcased in previous reports. These show what a possible high-end RDNA 4 GPU with multiple GCD chiplets would have looked like.
It is also reported that AMD's Navi 48 GPU is expected to feature 4 Shader Engines (Same as Navi 32) while Navi 44 will feature 2 Shader Engines (Same as Navi 33). These two GPUs are identified as the GFX1200 and GFX1201 IPs already.
Once again, we don't know the exact WGP/CU configuration per SE that AMD might opt for with its last remaining RDNA 4 GPUs but previous rumors have made some interesting claims in regards to their performance, you can read more on that here.
AMD RDNA Generational GPU Lineup
| Radeon Lineup | Radeon RX 5000 | Radeon RX 6000 | Radeon RX 7000 | Radeon RX 8000 |
|---|---|---|---|---|
| GPU Architecture | RDNA 1 | RDNA 2 | RDNA 3 / RDNA 2 | RDNA 4 |
| Process Node | 7nm | 7nm | 5nm/6nm | 5nm/3nm? |
| GPU Family | Navi 1X | Navi 2X | Navi 3X | Navi 4X |
| Flagship GPU | N/A | Navi 21 (5120 SPs) | Navi 31 (6144 SPs) | Navi 41 (Cancelled?) |
| High-End GPU | Navi 10 (2560 SPs) | Navi 22 (2560 SPs) | Navi 32 (4096 SPs) | Navi 48 (4 SEs?) |
| Mid-Tier GPU | Navi 12 (2560 SPs) | Navi 23 (2048 SPs) | Navi 33 (2048 SPs) | N/A? |
| Entry-Tier GPU | Navi 14 (1536 SPs) | Navi 24 (1024 SPs) | Navi 34 (1024 SPs)? | Navi 44 (2 SEs?) |
