It looks like AMD is heavily investing in stacked cache and chiplet technologies for their next-gen CPU & GPU designs. Based on a new rumor by Greymon55, it looks like after EPYC & Ryzen, AMD will be bringing stacked 3D Cache design to RDNA in the form of 3D Infinity Cache.
Next-Gen AMD RDNA GPUs Might Feature 3D Infinity Cache Technology – 3D Stacking Cache on MCM GPUs
With RDNA 2, AMD introduced its first-generation Infinity Cache architecture which is a fast and high-bandwidth on-die cache that the GPU can quickly access. The existing cache designs can be scaled up to 128 MB capacities and up to 2 TB/s bandwidth. With next-gen RDNA 3 GPUs, it has been rumored that the GPUs will double the amount of Infinity cache with Navi 33 expected to offer 256 MB and Navi 31 expected to offer up to 512 MB of Infinity Cache.
3D IFC
— Greymon55 (@greymon55) November 8, 2021
N31
N32— Greymon55 (@greymon55) November 8, 2021
The IFC on Navi 31 GPUs will be split between two chips since it is an MCM design so it’s still 256 MB per chip. The latest rumors now suggest that the Infinity Cache is also moving to a 3D stack design. So we aren’t just getting MCM GPUs with RDNA 3 but there’s also a possibility of getting stacking technology on the next-gen chips. So in total, AMD will have 3D cache technology on its entire lineup including Ryzen, EPYC, and Radeon.
AMD is also going to introduce its server aimed CDNA 2 GPUs today which will be the first to feature an MCM technology. So far, there have been no reports of Infinity Cache on the current CDNA design but it may be possible that future GPUs could include the same cache stacking technology as bandwidth demand increases.
AMD RDNA 3 Navi 3X GPU Configurations (Preliminary)
| GPU Name | Navi 21 | Navi 33 | Navi 32 | Navi 31 |
|---|---|---|---|---|
| GPU Process | 7nm | 6nm | 5nm/6nm | 5nm/6nm |
| GPU Package | Monolithic | Monolithic | MCM | MCM |
| Shader Engines | 4 | 2 | 4 (2 per GCD) | 6 (3 per GCD) |
| GPU WGPs | 40 | 20 | 40 (20 per GCD) | 60 (30 per GCD) |
| SPs Per WGP | 128 | 256 | 256 | 256 |
| Compute Units (Per Die) | 80 | 40 | 80 160 (Total) | 120 240 (Total) |
| Cores (Per Die) | 5120 | 5120 | 5120 | 7689 |
| Cores (Total) | 5120 | 5120 | 10240 | 15360 |
| Memory Bus | 256-bit | 128-bit | 192-bit | 256-bit |
| Memory Type | GDDR6 | GDDR6 | GDDR6 | GDDR6 |
| Infinity Cache | 128 MB | 256 MB | 384 MB | 512 MB |
| Flagship SKU | Radeon RX 6900 XTX | Radeon RX 7700 XT? | Radeon RX 7800 XT? | Radeon RX 7900 XT? |
| TBP | 330W | ~200W | ~300W | ~400W |
| Launch | Q4 2020 | Q4 2022? | Q4 2022? | Q4 2022? |
The AMD RDNA 3 ‘Navi 3X’ GPU-powered Radeon RX graphics card lineup is expected to offer up to 3x performance improvement over existing RDNA 2 offerings. It would mark a major leap forward for graphics evolution and now that AMD is already onboard with next-gen technologies such as FSR and Raytracing, expect a very heated next-gen competition between the red and green teams.
