AMD next-gen MCM RDNA 3 GPUs for the Radeon RX 7000 series graphics cards have been detailed once again by Moore's Law is Dead. While the information revealed is pretty much the same that we've heard over the past few months, what's new are the launch schedules which show that AMD will release its flagship variants as early Q4 2022.
AMD Radeon RX 7000 Graphics Card Launch Schedules Rumored: Navi 31 For Radeon RX 7900 Series In Q4 2022, Navi 32 For Radeon RX 7800 Series in 1H 2023
Based on the latest information from MLID, both, the AMD Navi 31 and Navi 32 GPUs will utilize an MCM solution but there's a possibility that the Navi 31 GPU could make use of 3D-Stacking while the Navi 32 GPU could make of a standard multi-die approach, similar to AMD's Instinct MI250X. It looks like Navi 31 might get a similar design as the Instinct MI300 GPUs which are going to feature a 3D-stacking technology that fuses the GPUs on top of the IO die. We have heard rumors of Infinity Cache being on a separate die so that might be what's going on here. As for Navi 32, it will carry on the same design approach as MI200 series. Both the Navi 31 and Navi 32 GPUs will be composed of 6nm IO (MCD) and 5nm GPU (GCD) chiplets.
As for the launch schedule, the AMD Navi 31 GPU will appear within the flagship Radeon RX 7900 series by end of Q4 2022. Do note that the Navi 33 GPUs based on 6nm Monolithic dies will be the first to hit shelves. The Navi 32 GPUs for the Radeon RX 7800 series will launch in the first half of 2023. Also, the reason why I don't believe Navi 33 GPUs will end up with the Radeon RX 7600 series branding and instead use Radeon RX 7700 series is simply the pricing.
There are rumors that the Navi 33 graphics cards will end up in the $400-$500 US range and they are meant to replace the existing Navi 21 parts. As such, it doesn't make sense to brand a high-end graphics card as a *600 series product.
https://twitter.com/greymon55/status/1519202316728950784
There was also a recent rumor about AMD Navi 31 featuring a total of 7 chiplets, one IOD, two GCD, and four MCD. So there will be two GCDs sitting on top of the IOD while the MCDs can either sit on top of the GCDs or the IOD. It will be one interesting GPU configuration to see and the start of the chiplet era in the gaming graphics consumer segment.
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?) |
AMD RDNA 3 Navi 31 GPUs For Radeon RX 7900 Series
The AMD Navi 31 GPU, the flagship RDNA 3 chip, would power the next-gen enthusiast cards such as the Radeon RX 7900 XT graphics card. We have heard that AMD will drop CU (Compute Units) in favor of WGP (Work Group Processors) on its next-gen RDNA 3 GPUs.
The Navi 31 GPU configuration shown here features two GCD's (Graphics Core Die) and a single MCD (Multi-Cache Die). Each GCD has 3 Shader Engines (6 in total) and each Shader Engine has 2 Shader Arrays (2 per SE / 6 per GCD / 12 in total). Each Shader Array is composed of 5 WGPs (10 per SE / 30 per GCD / 60 in total) and each WGP features 8 SIMD32 units with 32 ALUs (40 SIMD32 per SA / 80 per SE / 240 per GCD / 480 in total). These SIMD32 units combine to make up 7,680 cores per GCD and 15,360 cores in total.
The Navi 31 (RDNA 3) MCD will be linked to the dual GCD's via a next-generation Infinity Fabric interconnect and feature 256-512 MB of Infinity Cache. Each GPU should also feature 4 memory connect links (32-bit). That's a total of 8 32-bit memory controllers for a 256-bit bus interface.
AMD RDNA 3 Navi 32 GPUs For Radeon RX 7800 Series
The AMD Navi 32 GPU will be one of the two MCM GPUs featured in the RDNA 3 lineup. The GPU will feature two GCD's (Graphics Compute Dies) and a singular MCD (Multi-Cache Die). The die is very similar to the flagship Navi 31 GPU but has one less Shader Engine across each die. The AMD Navi 32 GCD is expected to utilize TSMC's 5nm process node while the MCD will be based on a 6nm process node. Rumors are that AMD has the option to select between Samsung and TSMC for the 6nm die.
Each GCD has 2 Shader Engines (4 in total) and each Shader Engine has 2 Shader Arrays (2 per SE / 4 per GCD / 8 in total). Each Shader Array is composed of 5 WGPs (10 per SE / 20 per GCD / 40 in total) and each WGP features 8 SIMD32 units with 32 ALUs (40 SIMD32 per SA / 80 per SE / 160 per GCD / 320 in total). These SIMD32 units combine to make up 5120 cores per GCD and 10,240 cores in total.
The Navi 32 (RDNA 3) MCD will be linked to the dual GCD's via a next-generation Infinity Fabric interconnect and feature 384 MB of Infinity Cache. Each GPU should also feature 3 memory connect links (32-bit). That's a total of 6 32-bit memory controllers for a 192-bit bus interface.
This would bring the performance of the AMD Radeon RX 7700 series above the RX 6800 and RX 6900 series, offering one big leap in graphics horsepower in games. This would also pump up the power numbers as the RX 6700 XT is currently rated at 230W but that could go up to 270-300W.
There have been several rumors stating that the upcoming RDNA 3 GPUs are going to outperform whatever NVIDIA has to offer in terms of rasterization performance and power efficiency. It looks like AMD will take the lead by offering the first MCM-powered GPUs under its Radeon RX graphics card lineup.
AMD RDNA 3 Navi 3X GPU Configurations (Preliminary)
| GPU Name | Navi 21 | Navi 33 | Navi 32 | Navi 31 | Navi 3X |
|---|---|---|---|---|---|
| Codename | Sienna Cichlid | Hotpink Bonefish | Wheat Nas | Plum Bonito | TBD |
| GPU Process | 7nm | 6nm | 5nm/6nm | 5nm/6nm | 5nm/6nm |
| GPU Package | Monolithic | Monolithic | MCM (1 GCD + 4 MCD) | MCM (1 GCD + 6 MCD) | MCM (TBD) |
| GPU Die Size | 520mm2 | 203mm2 (Only GCD) | 200mm2 (Only GCD) 425mm2 (with MCDs) | 300mm2 (Only GCD) 522mm2 (with MCDs) | TBD |
| Shader Engines | 4 | 2 | 3 | 6 | 8 |
| GPU WGPs | 40 | 16 | 30 | 48 | 64 |
| SPs Per WGP | 128 | 128 | 128 | 128 | 128 |
| Compute Units (Per Die) | 80 | 32 | 60 | 96 | 128 (per GPU) 256 (Total) |
| SPs (Per Die) | 5120 | 2048 | 3840 | 6144 | 4096 |
| ALUs (Per Die) | 5120 | 4096 | 7680 | 12288 | 16384 |
| Memory Bus | 256-bit | 128-bit | 256-bit | 384-bit | 384-bit x2? |
| Memory Type | GDDR6 | GDDR6 | GDDR6 | GDDR6 | GDDR6 |
| Memory Capacity | Up To 16 GB | Up To 8 GB | Up To 16 GB | Up To 24 GB | Up To 32 GB |
| Memory Speed | 16-18 Gbps | TBD | TBD | 20 Gbps | TBD |
| Memory Bandwidth | 512-576 GB/s | TBD | TBD | 960 GB/s | TBD |
| Infinity Cache | 128 MB | 32 MB | 64 MB | 96/192 MB | TBD |
| Flagship SKU | Radeon RX 6900 XTX | Radeon RX 7600 XT? Radeon RX 7700M? | Radeon RX 7800 XT? Radeon RX 7900M? | Radeon RX 7900 XTX | Radeon Pro |
| TBP (Max) | 330W | ~150W | ~250W | 335W | TBD |
| Launch | Q4 2020 | Q4 2022? | Q4 2022? | Q4 2022? | 2023? |
