NVIDIA GeForce 340.43 Beta Driver Patches 4K @ 60Hz Over HDMI 1.4

NVIDIA has silently implemented a workaround into the 340.43 beta driver for 4K 60Hz single-stream displays to be driven over a Kepler-powered HDMI 1.4 connection. Previously, 60Hz 4K was only achievable via DisplayPort 1.2 or HDMI 2.0, the latter being a standard that has yet to really reach the consumer market.

Chroma Subsampling

Chroma Subsampling reduces digital video signal bandwidth.

The above image shows an example of chroma subsampling, the compression method used to trim down the bandwidth of the outbound video signal. On the right, 4:4:4 is the sampling rate of a full chroma resolution. On the left, 4:2:0 is what NVIDIA has chosen to push the massive resolution over HDMI 1.4.

ASUS PB287 4K Display

While it is technically 1/4 the color range of full resolution, it’s not as cut and dry as losing 3/4 of the image quality. DVD’s, Blu-Ray, and most H.26x video is natively stored at 4:2:0 sampling. This isn’t going to be a headlining feature of Kepler cards or 4K panels, but for early adopters who’d value a faster refresh rate over color accuracy, this should be welcome news.

  • Richy Rich

    Can anyone please help me with this question?

    Currently, lets say the GTX680 2GB can run Metro 2033 (4k Max settings) at only 12 FPS (4:4:4). Now with this driver update and the output colour reduced to 4:2:0, would you expect to have a better FPS? If so, what could you realistically expect?

  • anon

    It will clearly impact on Gaming and desktop use. Chroma subsampling has tremendous effects upon GUI.
    Have you wondered why it always look different a gaming video from a game experience? Why is so usual to rise up the sharpen bar for those kind of videos?
    Why most of tv makers spend money in complex and expensive chroma upsampling?

    • basroil

      You do realize that the screen will look no worse than 1080p right? Not to mention that “desktop use” isn’t really an issue since this is limited to 4k TVs, which are meant for video and not applications.

      While game gui might indeed see issues (bleeding, discoloration, etc), 60fps gaming is not really an option right now, and 2560×1440 actually looks far better at the same 60fps mark. When SLI/CF systems are capable of driving 4k at high/ultra settings, then HDMI2.0 will be out and we won’t have this issue when connecting to TVs. Monitors never had this issue because most 4k monitors have Displayport, which can natively drive 4k at 60Hz without resorting to lowering the resolution.