Cutting corners: When Google announced its Stadia cloud streaming platform in March, it promised a 4K 60 fps HDR gameplay using AMD processors and GPUs. Assuming that the 2.7 GHz processor was a little underpowered in 4K, fans had hoped that the GPU would catch up with it using AMD's future 7-nm Navi platform, but it looks like it's not not the case.
This time, Google set things up by listing Stadia in Khronos' Vulkan API-compliant list of products under the name "Google Play Platform 1 (AMD GCN 1.5)". GCN, or Graphics Core Next, is the basic AMD architecture and GPU instructions their GPUs are built on. GCN 1.3 was the R9 Fury series, GCN 1.4 was the RX 400 series and GCN 1.5 was Vega. The Radeon VII brought them to 1.5.1, and Navi should stay at 1.5.1 or more likely to create the 1.6 family. GCN 1.5 limits the stages to 14 nm Vega.
When announcing the Stadia, Google revealed five facts about the GPU used: 10.7 TFLOPS, 56 units of computation, a HBM2 memory reaching 484 GB / s and 8 GB of memory. Knowing that the graphics processor must be based on a Vega product, it seems that the most likely candidate is the Vega 56, which also has 8 GB of HBM2 memory and 56 computing units. While the Vega 56 was only 410 GB / s, Google seems to have chosen to update it to reach the memory of 484 GB / s used by Vega 64.
While Vega 56 only has 8.3 TFLOPS when it runs at its base clock of 1 156 MHz, to reach 10.7 TFLOPS, it should run at 1493 MHz, just a hair's breadth above specified boost clock of 1,471 MHz. It still seems a bit surprising that Google chooses one of the hottest and most energy-hungry GPUs available for its data centers, but AMD may have found a way to optimize it for loads working in the cloud.
Assuming that the Stadia GPU is based on the Vega 56, Google's assertions about the 4K game at 60 fps seem somewhat dubious. In TechSpot tests, Vega 56 averages 43 frames per second in our 25-game test suite with only Overwatch, Quake Champions, Hitman and Doom breaking the 60-frame-per-second barrier. Even with upgrades, Stadia content in 4K 60fps will likely be limited to the popular and popular Battle Royal titles.