But my 5” touchscreen monitor can...

If it's really 10-20s, I'm guessing it's because it's because it's cycling through the various input sources looking for a signal.

Might be that, also the computer itself might be another reason. But who cares? Why doesn't the monitor just re-establish the last known good connection quickly?

But it could just look at all of the input sources at the same time. And anyway, these are solid state electronics, not hamsters and flywheels. Taking seconds to send "give me electrons" and for the other side to say "here are some electrons" is bonkers.

Being able to observe all inputs sources at the same time requires extra hardware(more utilisation of the FPGA resources), considering only one input is connected to the display at a time. So it's probable that the check is sequential.

"More" isn't a meaningful qualifier without a quantifier. I'm not convinced that it would take more than $0.01 worth of resource. I could even see doing it in a purely analog fashion with an extremely basic component like a mosfet. If a pin goes high because the computer responded to your request to send electrons, it sets the corresponding channel.

> So it's probable that the check is sequential.

It's a user unfriendly design for the process to be "send request, wait 5 seconds, send request on next channel, wait 5 seconds, send request on next channel, ..." when it could instead be sending requests across all channels rapidly and then that getting a response on a particular channel _activates_ that channel by analogue means.

I know you’re just guessing, but if that’s what happens, why don’t they just default to the last source used and start the cycling only if nothing is detected there?

I have auto-input select disabled since I only use my monitor with a dock. Still takes 15 seconds.

Why does it take 10-20s even if it is cycling through all the inputs though?

That's on the monitor, whatever process it is using to scan for input, warm up, or other needs. Buying a cheap offbrand monitor or something low end has drawbacks.

10 to 20 seconds? What monitor do you have? All decent monitors have a maximum of 5 seconds.

Unfortunately the very best LCD monitors currently all take pretty long to start up.

The Asus PG27UQ (regarded as the current-best consumer 27" 4K LCD) takes almost 20 seconds to start up, presumably to initialize a bunch of state for its FPGA.

LCD? What year is this, 2005? I have LED for over a decade now, and all my friends as well.

No, you don’t. Unless you are using an OLED screen, you have an LED-backlit LCD screen. Vendors call them LED monitors because it sounds more high tech than old LCD monitors.

That said, LED backlit LCDs are better than the old CCFL screens.