How can old Ethernet cables can handle transmitting the data needed for 4K 60hz video, but we need new HDMI 2.1 cables to do the same thing?

Question

How can old Ethernet cables can handle transmitting the data needed for 4K 60hz video, but we need new HDMI 2.1 cables to do the same thing?

In: Technology

Answer 1

You’re probably thinking of compressed video.

To get 4k60, HDMI 2.1 has 18Gbps of bandwidth. Regular old ethernet cable and network cards generally max out at 10Gbps, which is the same as HDMI 1.4. Not enough for uncompressed 4k60.

But video over a network is almost always compressed, which substantially reduces the amount of bandwidth it needs. That’s probably the 4k60 over ethernet you are thinking of. But that adds compression artifacts and latency, which you don’t want for a monitor output. So HDMI uses uncompressed video.

Now ethernet can go above 10Gbps, but the network cards get very expensive very quickly. To reach 25Gbps you need to spend $350. So if you wanted to replace HDMI with ethernet cables you would need to add $350 to the cost of your TV/Monitor and $350 to the cost of every device as well.

That’s why you have HDMI instead, it’d designed to be both high bandwidth and cheap.