eli5: how does vga, dvi,hdmi, displayport,usb control each pixel of a monitor if the cable doesn’t seem to have a wire for each and every pixel?

Question

eli5: how does vga, dvi,hdmi, displayport,usb control each pixel of a monitor if the cable doesn’t seem to have a wire for each and every pixel?

In: Technology

Answer 1

I’ll skip VGA as it’s analog.

The particulars vary by protocol, but really – DVI/HDMI and DisplayPort just sends things over a data stream. You don’t need an individual pin for every piece of data you’re sending, just like you don’t need a pin on an ethernet cable for each one-way network session you’ve got open – it’s just encoded in a way that gets you the resolution you need, at the refresh rate you need. HDMI 2.0 has a max bandwidth of 18Gbps (~1,800,000,000,000 bits/sec)- That’s plenty of bandwidth to send say, 8,294,400 pixels (3840×2160) at 60hz and a color depth that results in 48 bits/pixel.

There’s more to it and the bandwidth used is a lot higher, but that’s the oversimplified version.