At the moment, we already have relatively reliable information that the large Navi GPU, namely “Navi 21”, will supposedly have 80 execution units at its disposal, which will eventually give us 5120 stream processors. If you refer to the formula of the current cards based on the Navi architecture (Radeon RX 5700XT).
In fact, immediately after the publication of the alleged characteristics of the “Navi 21” chip, information appeared on the network that the AMD Radeon RX gaming video cards based on the “Big Navi” GPU will be produced in versions with 12 GB and 16 GB of video memory of the GDDR6 standard (memory bus width 384 and 512 bits respectively).
In addition, the already well-known and relatively reliable insider _rogame, shared rumors on his Twitter account about as many as four versions of the Navi 21 chip:
- Navi21 XTX
- Navi21 XT
- Navi21 XL
- Navi21 XE
_rogame assumes that the youngest GPU will be “Navi21 XE”, and its bus width will be cut from 512 to 320 bits, which can cause the appearance of a 10-gigabyte version of the pre-top video card. Thus, it is possible that a 12-gigabyte, 384-bit video adapter will be a card with a Navi21 XL GPU on board.
However, frankly, the 10GB version of AMD’s graphics card is hard to believe. What can not be said about the very real 12 GB (Radeon RX 6800XT?).
Nevertheless, it is necessary to take into account the following fact: AMD is unlikely to put under the knife only the memory bus, bypassing the GPU execution units. And not surprisingly, this possibility was also noted by the source of the rumors _rogame. He invited his subscribers to choose one of the options for reducing the performance of a more affordable adapter. However, Twitter users did not agree and voted for the fact that the cheaper video card would practically not undergo additional simplification from the execution units.
We, in turn, are not so optimistic. Most likely, if the rumors about a 12 GB version of the Radeon RX 6900XT (or Radeon RX 6800XT?) card are confirmed, it will lose not only bandwidth but at least 10-20% of execution units (stream processors and texture units; rasterization units are unlikely to go under the knife).
Information similar to our opinion is already circulating on the network (however, it is actually not confirmed by anything):
According to it, a card with 12 gigabytes of memory (presumably Radeon RX 6800XT) will lose as many as 896 stream processors, and, accordingly, a considerable number of texture units.
Radeon RX “Big Navi” 6900XT presumptive spec list:
| Graphics Card | Radeon RX Vega 64 | Radeon VII | Radeon RX 5700 XT | Radeon RX ‘Big Navi’ |
|---|---|---|---|---|
| GPU architecture | 14nm Vega (Vega 1st Gen) | 7nm Vega (Vega 2nd Gen) | 7nm Navi (RDNA 1st Gen) | 7nm+ Navi (RDNA 2nd Gen)? |
| Executive blocks | 64 | 60 | 40 | 80? |
| Stream Processors | 4096 SPs | 3840 SPs | 2560 SPs | 5120 SPs? |
| TMUs / ROPs | 256 / 64 | 240 / 64 | 160 / 64 | 320 / 64? |
| Base frequency | 1247 MHz | 1400 MHz | 1605 MHz | Unknown |
| Maximum boost frequency | 1546 MHz | 1802 MHz | 1905 MHz | Unknown |
| Game boost frequency | ~1450 MHz | 1750 MHz | 1755 MHz | Unknown |
| Theoretical performance | 12.66 TFLOPs | 13.44 TFLOPs | 9.75 TFLOPs | Unknown |
| The amount and type of video memory | 8 GB HBM2 | 16 GB HBM2 | 8 GB GDDR6 | 16 GB GDDR6? |
| Video memory bus | 2048-bit | 4096-bit | 256-bit | 512-bit |
| Bandwidth | 484 GB/s | 1024 GB/s | 448 GB/s | 896-1024 GB/s? |
| TDP | 295W | 295W | 225W | 250-300W? |
| Price | $499 US | $699 US | $399 US | Unknown |
| Date of issue | August 7, 2017 | February 7, 2019 | July 7, 2019 | November 2020? |
Treat all the information received with extreme caution, so all the above characteristics are just rumors, and some are even speculations against the backdrop of rumors.
Source: WccfTech
