Last week, we published the hardware spec for Microsoft's next Xbox - Project Scorpio. However, there was one little detail we held back, an aspect of the new console we didn't want to get lost in the noise. In the here and now its applications will be limited, but in the fullness of time, it may help to bring about a profound shift in how displays interface with games hardware. To cut a long story short, Scorpio supports AMD's FreeSync - and the upcoming variable refresh rate support baked into the next-gen HDMI 2.1 spec.
So what's the big deal here? In an ideal world, every single console game would run at 60fps, perfectly sychronised with the refresh rate of the attached display. This would result in a super-smooth, low latency gameplay experience - something you can see in the here and now in titles including the Forza Motorsport series and Halo 5. However, if a game targets 60fps and doesn't consistently hit the target, the experience is compromised in one of two ways.
First of all, if the game runs with v-sync enabled, frames are dropped and this introduces noticeable judder - what's happening here is that the game only has a small window in which to synchronise with the screen. If a frame renders over its 1/60th of a second budget, the GPU stalls, waiting for the next refresh. Alternatively, the developer may simply decide to drop synchronisation with the screen - when this happens, highly intrusive, ugly screen-tearing kicks in.
Adaptive refresh technology like AMD's FreeSync completely eliminates tearing and reduces stutter significantly by allowing the GPU to trigger the display refresh instead of adhering to a hard and fast 60Hz cycle. Essentially, the screen produces the next image immediately after the GPU finishes rendering it. The technology was pioneered by Nvidia's G-Sync, but it's the open standard variants - FreeSync and the upcoming HDMI 2.1 implementation - that Scorpio aims to supports. In fact, Microsoft has actually implemented the FreeSync 2 standard, meaning compatibility with HDR and full support across the range of potential frame-rates. Paired with a supported screen, this will even eliminate tearing on games running with adaptive v-sync with frame-rates under 30fps, something not supported on most FreeSync 1 screens (VRR range varied on a per-screen basis, with 40Hz to 60Hz commonplace).
