More Features: DX12, VR Direct, HDMI 2.0
NVIDIA is touching on the virtual reality phenomenon as well, and they put a brand on its set of features to target devices like the Oculus Rift. VR Direct attempts to improve the user experience of VR in a handful of interesting ways.
First, asynchronous warp is the ability for the GPU driver to circumvent much of the latency pipe of VR displays by rendering a frame ahead of time and then warp it slightly based on information from the game engine and driver stack. Essentially the GPU is "guessing" on what data the next frame will need then slightly adjusting it in post (very quickly) to match the expected result. The result is less time between the input from the user and the display updating to reflect that action.
Another interesting change is support for VR SLI, which moves from an AFR (alternate frame) method to one where each GPU renders for a different eye. This is, more or less, a return of the split frame rendering (SFR) and NVIDIA claims this offers lower latency yet again – the major goal for all VR optimization.
Maxwell and GM204 are the first GPUs to support upcoming DX12 feature sets as well. More on that later.
The various video engines on GM204 also see some nice upgrades as well, starting with support for HDMI 2.0, capable of running displays at 4K resolution and 60 Hz with the full 4:4:4 color space. This makes the GTX 980 and GTX 970 the first two graphics cards to support HDMI 2.0 TVs.
Reference outputs from the GTX 980 and GTX 970 (though none of the 970s I have seen follow the reference design) have a new, and welcome configuration update.
The GTX 980 reference cards that I have here include three full-size DisplayPort outputs, a full-size HDMI 2.0 port, and a dual-link DVI connection. That sets up the GTX 980 perfectly for users looking for multiple G-Sync displays but does limit the amount of air that can flow from the card and out of the case somewhat.
Even though you have 5 outputs, the GPU can support 4 simultaneous displays but can drive resolutions up to 5120×3200 at 60 Hz. GM204 is ready for those newly announced Dell 5K monitors it seems. Also note support for eDP 1.4 – likely in there to be sure NVIDIA cards will be able to run the upcoming Adaptive Sync standard from VESA.
The embedded video encoder in Maxwell is updated as well to include some additional performance and support. H.265 encoding is there (HEVC) and the H.264 encoder now is able to handle 4K video at 60 FPS. Yep, and it works in ShadowPlay. I can't wait to see everyone's 4K captures being pushed up to YouTube!