AMD Radeon RX 7900 XT To Feature RDNA 3 “Navi 31” GPU Core & 20 GB GDDR6 VRAM
The AMD RDNA 3 GPU lineup will kick off first with high-end offerings based on the Navi 31 MCM chip. The chip will be featured in enthusiast-class Radeon RX 7000 graphics cards including the RX 7900 XT which we have received new information about from our sources. As per the details, the AMD Radeon RX 7900 XT graphics card won’t be the top model but it will feature 20 GB of GDDR6 VRAM. Our source reports that AMD’s Radeon RX 7000 “RDNA 3” GPUs may exceed expectations & while there are conflicting rumors (here and here), it looks like the end result might be a far better product than anticipated. We have also come to know that the AMD Radeon RX 7900 XT originally featured 24 GB of memory capacity before being downgraded to 20 GB. The Full-Fat 24 GB & Top Navi 31 bin will be aimed at NVIDIA’s full-Fat Ada die (the RTX 4090 Ti). AMD seems very confident that with 20 GB and a slightly cut-down MCM chip, they will sit in a comfortable position against the RTX 4090 and may even outperform it in pure rasterization performance while bringing a big jump in RT performance versus the existing RDNA 2 GPUs. With the Radeon RX 7900 XT utilizing 20 GB of memory, it would indicate that the rumors regarding a higher-end SKU seem to be true. AMD has already started using the *950 XT convention in its last RDNA 2 generation of GPUs so an RX 7950 XT is surely happening. Angstronomics also reported on similar details a while back in their juicy article over here which you should definitely check out.
AMD Navi 31 “Plum Bonito” GPU Configuration
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. Each WGP will house dual CU (Compute Units) but with twice the SIMD32 clusters as opposed to just 2 on each CU within RDNA 2. Rumors are that AMD has the option to select between Samsung and TSMC for the 6nm die.
AMD Navi 31: 12288 Cores, 384-bit Bus, 192 MB Infinity Cache, 308mm2 GPU Die @5nm AMD Navi 21: 5120 Cores, 384-bit Bus, 128 MB Infinity Cache, 520mm2 GPU Die @7nm
According to the latest information, the AMD Navi 31 GPU with RDNA 3 architecture is expected to offer a single GCD with 48 WGPs, 12 SAs, and 6 SEs. This will give out a total of 12,288 SPs or stream processors. This is an increase of 2.4x in cores compared to the 5120 SPs featured on the Navi 21 GPU. The GPU or the Navi 31 GCD is said to measure 308mm2 and will come packaged on TSMC’s 5nm process node. The cut-down variant will feature 42 WGPs or 10,752 cores and 5 MCDs for 80MB Infinity Cache across a 320-bit bus interface. The Navi 31 GPU will also carry 6 MCD’s which will feature 16 MB Infinity Cache per die and are also likely to carry the 64-bit (32-bit x 2) memory controllers that will provide the chip with a 384-bit bus interface. While this equals 96 MB of Infinity Cache which is lower than the 128 MB featured on the current Navi 21 GPUs, there’s also a 3D-Stacked solution in the works which was pointed out recently and that would double the Infinity Cache with 32 MB (16 MB 0-hi + 16 MB 1-hi) capacities for a total of 192 MB of cache. This is a 50% increase versus the current Navi 21 design and it also makes Navi 31 the first GPU with both, chiplet and 3D stacked designs. These chiplets or MCD’s will be fabricated on TSMC’s 6nm process node and measure 37.5mm2 each. Now, this is going to result in a higher power draw and AMD seems to have confirmed this much that their next-generation graphics card lineup will feature higher power consumption but they will still be a more efficient option than what NVIDIA has to offer. The AMD Radeon RX 6950 XT already has a TBP of 335W so for a >2x performance gain. The cards are expected to retain their dual 8-pin plug input for power and feature an updated triple-fan cooling design which is slightly taller than the one currently in use.
AMD Radeon RX 7900 Series “Official” Specifications:
AMD will be unveiling its RDNA 3 GPU architecture and the Radeon RX 7000 graphics cards on the 3rd of November. They have a full Livestream planned which you can read more details about here.
