4:2:0 sampling on the other hand is not normally used for the last stage of transmission between source and sink devices – in fact HDMI didn’t even officially support it until recently – and is instead used in the storage of source material itself, be it Blu-Ray discs, TV broadcasts, or streaming videos. Most HDMI PC-to-TV setups to date use RGB or 4:4:4 sampling, both of which are full resolution and functionally lossless. The use of chroma subsampling is as old as color television itself, however the use of it in this fashion is uncommon. By using this sampling mode manufacturers are able to transmit an image that utilizes full resolution luma (brightness) but a fraction of the chroma resolution, allowing manufacturers to achieve the necessary bandwidth savings. Specifically, manufacturers are making use of Y'CbCr 4:2:0 subsampling, a lower quality sampling mode that requires ¼ the color information of regular Y'CbCr 4:4:4 sampling or RGB sampling. To accomplish this, manufacturers are making use of chroma subsampling to reduce the amount of chroma (color) data that needs to be transmitted, thereby freeing up enough bandwidth to increase the image resolution from 1080p to 4K.Īn example of a current generation 4K TV: Sony's XBR 55X900A Lacking the available bandwidth to fully support until the arrival of HDMI 2.0, the latest crop of 4K TVs such as the Sony XBR 55X900A and Samsung UE40HU6900 have implemented what amounts to a lower image quality mode that allows for a signal to fit within HDMI 1.4’s 8.16Gbps bandwidth limit.

These setups were previously limited to due to HDMI bandwidth availability, and while those limitations haven’t gone anywhere, TV manufacturers and now NVIDIA have implemented an interesting workaround for these limitations that teeters between clever and awful.

However as it turns out the situation is not quite cut & dry as it first appears, so there is a notable catch.įirst discovered by users, including AT Forums user saeedkunna, when Kepler based video cards using NVIDIA’s R340 drivers are paired up with very recent 4K TVs, they gain the ability to output to those displays at over HDMI 1.4. An interesting feature has turned up in NVIDIA’s latest drivers: the ability to drive certain displays over HDMI at This is a feat that would typically require HDMI 2.0 – a feature not available in any GPU shipping thus far – so to say it’s unexpected is a bit of an understatement.

Good video card for 4k tv