[Leica] Current State of Displays?

[imra at iol.ie (Douglas Barry)]

Fascinating, thanks Brian!

Douglas


On 03/08/2017 19:31, Brian Reid wrote:
> There is an electronics/mathematics issue that factors into large 
> displays. It's why I have an iMac and not an external display.
>
> At any given time, the computer and electronics industry has some 
> means that is the fastest for rapidly and reliably moving data over a 
> cable. USB has never been in contention, but FireWire, Thunderbolt, 
> DVI, and Fibre Channel have all been candidates for "the fastest and 
> best" at one time or another. Ethernet, at any speed, has never been 
> the fastest.
>
> The 5K Retina display has about 15 million pixels. Each pixel can have 
> about 10,000 different values (this number is a little soft). So one 
> screen-shot on a 5K Retina display is 150 thousand million bits, about 
> 150 gigabits.
>
> So to keep an iMac Retina display happy you have to feed it about 150 
> gigabits for each screen refresh. People like 30 or 60 screen 
> refreshes per second.
>
> By putting some fast computing inside the display itself you can get 
> away with not having to send the whole 150 gigabits every time. Which 
> is a good thing, bdcause 150 gigabits sent 50 times per second is 7500 
> gigabits per second.
>
> If you try to send 7500 gigabits per second over a cable, you run into 
> all manner of bad-ass electrical engineering issues. When good 
> electrical engineers are speaking in hushed tones of the expertise of 
> a master, they sometimes say "she can do terabit connections".
>
> If you have an external display, then you have to have a cable that 
> connects your computer to your display. That cable has to have at 
> least one connector on it, so that it can plug into the computer. 
> (Often the cable is permanently attached to the display to avoid 
> having to use a connector there). Connectors are the black beast of 
> high-speed signal transmission. They are much more difficult to design 
> than cables, and cables themselves are hard.
>
> In an iMac, the circuitry that generates the display signal is about 1 
> inch away from the screen, and you can make multiple connections if 
> you are tricky. That way you won't have to send the whole 7.5 terabits 
> per second over one cable.
>
> It's much easier to design and build the ultra-high-speed transmission 
> capability in an all-in-1 design like the iMac than it is to design 
> and build something that uses, say, an Eizo air traffic control 
> display connected to a computer 5 feet away.
>
> This is more or less why an iMac with a killer screen is just a few 
> thousand dollars, while an air-traffic-control display system with 10 
> good screens (though not as good as the iMac) is a few million dollars.
>
>
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