AMD silicon lies at the heart of the Xbox Series X (opens in new tab), Xbox Series S, and PlayStation 5 (opens in new tab), which means the red team is hard at work to produce as much RDNA 2 and Zen 2 silicon as it can to meet demand. In doing so, it is likely amassing quite the collection of broken chips, those with a few (or a few million) transistors off the norm. The chips that don't quite make the cut may end up in this desktop kit before you: the AMD 4700S.
The AMD 4700S is nearly the complete package for a PC (via Videocardz (opens in new tab)). Under the included cooler lies an AMD Zen 2-powered CPU, an eight-core chip, which puts it in line with the latest consoles and some Ryzen CPUs. Alongside that is the tell-tale sign of this chip's console origin: it comes with either 8GB or 16GB of GDDR6 memory.
Modern consoles use shared memory pools, namely GDDR6 today, which isn't something you'd find on any gaming PC. While GDDR6 offers plenty of bandwidth for GPUs, DDR4 is much better suited to the task of general system memory thanks to low latencies. So there's no real reason for AMD to produce a desktop kit with GDDR6 memory unless it already had the chips lying around.
From what I can tell eyeing up images from Disclosuzen on Twitter (via TechPowerUp (opens in new tab)), the memory must be located on the underside of the motherboard, beneath the extended rear heatsink. That doesn't give the memory the optimal cooling solution, although this machine is hardly at the forefront of PC performance anyways.
With the memory likely located on the underside of the PCB, this looks the part of the PS5 SoC. Twitter leaker rogame also spots matching traces between the 4700S and the PS5, suggesting this chip may have once been destined for Sony's console. Perhaps AMD and Sony's chipmaking agreement has some stipulation in it whereby AMD can use or purchase chips Sony has no use for, but we can't say for sure.
I'm fairly sure it's a PS5 APU. Just check the PCB traces for the memory. https://t.co/QvZhX4wBMc pic.twitter.com/fS7iQfYfTGJune 28, 2021
Note the lack of Ryzen branding here too—this isn't technically a Ryzen product despite sharing the Zen 2 architecture with AMD's Ryzen 3000 chips. AMD's 4700S page does feature the painted circle logo I had assumed to be the Ryzen logo, but perhaps it's representative of the Zen architecture instead. Either way, AMD is clearly trying to avoid the Ryzen brand here.
To build out the entire kit, the CPU and memory are paired with a fairly basic motherboard. It features two SATA ports, a 1Gbps LAN port, eight USB ports, basic audio out from the I/O, and a couple of headers for extra USB connections. There's no M.2 NVMe port, however, and only one PCIe 2.0 x4 slot for a single GPU.
You'll have to provide one of those yourself, though. This kit doesn't come with any form of GPU. If this were a chip ripped right out of a console, it would feature a working RDNA 2 GPU with a beefy compute unit count—56, 36, or 20, depending on the console—yet here that's been entirely disabled, meaning a graphics card of some description is required.
It's a shame really, an APU with console graphics would be immense.
There are only a few graphics cards listed with official compatibility with the 4700S: AMD's RX 500-series and Nvidia's GT 710, 730, and GTX 1050, 1050 Ti, and 1060. Further compatibility is not specified, but it's likely the board's low PCIe bandwidth is to blame for the GPU restrictions. You can read up on the system's specs within its installation and warranty booklet (PDF warning) (opens in new tab).
Not that you'd want to build a gaming PC around this board anyways. We suspect its performance wouldn't be quite up to scratch with the latest gaming machines.
In graphics cards, wafers that don't quite make the grade are generally why we end up with cards like the GeForce RTX 3060 Ti (opens in new tab), built with a slightly less capable version of the GA104 GPU which would otherwise go into an GeForce RTX 3070 (opens in new tab). Microsoft will employ the same tactic with chips that don't making the cut for the Xbox Series X, instead finding a home in the Xbox Series S. But if you ever wondered what happens to all the disused chips and non-functional parts with no clear use in console-land, the AMD 4700S should give you some idea of where they end up.
Waste not, want not.