Introducing the state-of-the-art of watch graphics.
Imagination Technologies, the maker of the PowerVR graphics processor IP found in Apple's iPhone and iPad A-series chipsets, has announced the PowerVR G6020, which is aimed at low-end smartphones and... high end smartwatches. According to AnandTech:
From a design perspective, the G6020 is aimed at very simple desktop workloads – the Android UI, wearable interfaces, etc. Imagination has essentially built the bare minimum GPU needed to drive a 720p60 display, taking out any hardware not necessary to that goal such as compute and quite a bit of geometry throughput. What remains is enough of a ROP backend (pixel co-processor) to drive 720p, and the FP16 shading resources to go with it.
The end result of their efforts is designed to be an incredibly small and incredibly low power OpenGL ES 3.0 GPU for devices that fall in the cheap/small range. G6020 is only 2.2mm2 in size on 28nm, making it similar in size to ARM's Cortex-A7 CPU cores (a likely pairing target). And power consumption is low enough that it should be able to just fit into high-end wearables.
Until the inevitable teardowns, it'll be hard to know for sure what GPU Apple is using in the Apple Watch's S1 computer-on-a-chip. Since the company has such a significant history with the PowerVR, and Imagination has chips like the G6020, it may at least give us a clue as to what sorts of capabilities and power efficiencies are available in cutting edge ultra-ultra-mobile graphics these days.