Igor Wallossek from Igorslab has shared what appears to be a board design of an as yet unreleased RDNA 3 based graphics card, most likely that of a Radeon RX 7900 XT.
The diagram could represent AMD’s next flagship, the Radeon RX 7900 XT. Although we don’t know if this PCB layout is from a reference or a custom model, we see AMD’s Navi 31 GPU with seven chiplets, one GCD and six MCDs, plus 12 VRAM chips. Each space can be filled with 1GB or 2GB of GDDR6 giving us a total of 12GB or most likely 24GB of memory since this is a top tier product. As far as we know, AMD still uses GDDR6, unlike Nvidia’s GDDR6X.
The board is powered by three eight-pin power connectors, which means a maximum power consumption of 525W (150W wired plus 75W via PCIe). This does not rule out the possibility of AMD moving to 16-pin (12VHPWR) connectors. Power is then covered at lower voltages (required for GPU, VRAM, etc.) using 21 phases, 16 of which operate in tandem for a total of eight phases for GPU, two for memory, two for power. other components like controller memory and one for the I/O bus.
Note that the following sketch is based on real circuit boards and plans according to the leak, but the source cannot be verified.
In terms of connectivity, we have three DisplayPorts and one HDMI, most likely DisplayPort 2.0 and HDMI 2.1. Anything less would be a step backwards from current graphics products.
According to the latest reports, the Radeon RX 7900 XT is expected to feature a full Navi 31 GPU with 12,288 stream processors fabricated using TSMC’s 5nm. As said before, this GPU is made up of a GCD (Graphics Complex Die) and six MCDs (Memory Complex/Controller Die). Each MCD contains some amount of Infinity Cache – presumably 64MB or 96MB per chip. Not to mention the 24 GB of GDDR6 at 18 Gbit/s on a 384-bit wide bus.
While AMD still manages to keep its upcoming Radeon 7000 specs under wraps, we should start to see more leaks after the release of Zen 4 processors. Sit down and get comfortable, things are about to get interesting.