Please note that this post is tagged as a rumor.
AMD Navi 33 might be bigger than some might expect
Over at Wild_C‘s Twitter one can find beautiful renders of the Navi 3X GPU family.
These renders are not only based on the latest information such as AMD confirming six MCD’s for Navi 31, but also designed to be somewhat within the same scale. As we know, AMD is working on at least three Navi 3X GPUs for its Radeon 7000 series. Two of which will be based on a chiplet design with GCD (Graphics Core/Compute Die) and MCD (Memory Complex/Compute Dies). This means that design and size approximation are a bit more difficult than before.
It is not yet confirmed how large Navi 3X GPUs will be, however, recently rumor of Navi 31 GCD size has added some variables for speculation and educated guesses. Wild_C came up with the following die sizes, which as he says, are just a rough approximation.
I should probably list the die sizes used as well:
Navi33 = 20.5 * 19.5 = 400mm²
Navi31/32 MCD = 4.68 * 9.36 = 44mm²
Navi32 GCD = 13.1 * 20.1 = 263mm²
Navi31 GCD = 13.1 * 28.2 = 369mm²
Navi32 Total = 439mm²
Navi31 Total = 633mm²
Don’t expect these to be exact though
— Wild_C (@_wildc) July 21, 2022
AMD Navi 31 is the flagship GPU based on RDNA3 architecture, featuring as many as 48 WorkGroup Processors (WGP) and up to 12288 Stream Processors. It is designed to support six MCDs sitting right beside the GPU, which is somewhat similar approach to GPUs with High Bandwidth Memory. AMD has been pioneering such designs for a long time now (Fiji, Vega), but here memory is not located on the GPU package, but the controllers and Infinity Cache are. This GPU would have a GCD die size within 350 to 370 mm², which suggest that the full GPU (not package) might be somewhere in between 590 and 630 mm².
AMD Navi 32 is very similar to Navi 31, except it has fewer MCDs and fewer cores. This chip should offer up to 32 WGPs and up to 8192 Stream Processors. It is expected to be around 440 mm² large, from this 260 mm² is just the GCD alone.
The slowest RDNA3 GPU known as Navi 33 wouldn’t be much smaller than Navi 32. However unlike the previous chips, this one is not based on chiplets but on an old-fashioned monolithic design. Furthermore, it is not using TSMC 5nm process but only 6nm. What this essentially means is the GPU might be cheaper to make (no advanced packaging required), but the design Graphics Complex or Infinity Cache to be fused together. All that makes the GPU larger.
AMD RDNA3 architecture should be revealed in the fourth quarter this year. It is believed that Navi 31 will be the first GPU to take shed its cover followed by Navi 32 and Navi 33 later.
|RUMORED Specs of AMD RDNA3 GPUs|
|Fabrication Node||TSMC 5nm + 6nm||TSMC 5nm + 6nm||TSMC 6nm|
|Architecture||AMD RDNA3||AMD RDNA3||AMD RDNA3|
|GPU Package||Multi-Chip-Module (MCM)||Multi-Chip-Module (MCM)||Monolithic|
|GPU Size||≈ 630 mm² (GCD: 370 mm²)||≈ 440 mm² (GCD: 260 mm²)||≈ 400 mm²|
|Chiplet Configuration||1x GCD + 6x MCD||1x GCD + 4x MCD||–|
|RDNA Workgroups (WGP)||48||32||16|
|Memory & Bus||24GB GDDR6 384-bit||16GB GDDR6 256-bit||8GB GDDR6 128-bit|
|Memory Bandwidth||864 GB/s (18 Gbps)||576 GB/s (18 Gbps)||288 GB/s (18 Gbps)|
|Infinity Cache||192 MB||128 MB||96-128 MB|
|PCIe Interface||PCIe Gen5||PCIe Gen5||PCIe Gen5|
|Release||Q4 2022||Q4 2022/Q1 2023||Q4 2022/Q1 2023|
|Rumored SKU||Radeon RX 7900XT||Radeon RX 7700XT||Radeon RX 7600XT|
|All information based on rumors. (Updated: July 22, 2022)|