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Ask HN: Can you recommend an “instant-switch” Monitor? Does one exist?

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Re: Ask HN: Can you recommend an “instant-switch” Monitor? Does one exist?

#51

Post by kimburgess »

Not on a monitor (that I'm aware of), but it is a major feature of signal distribution equipment for installed AV and broadcast.

A large part of the delay that you are seeing is from EDID negotiation and HDCP. This happens of the 100kbit/s DDC channel and requires a bit of back and forth. On the above systems this is pre-negotiated so that switching can take place across a single frame.

A lot of that equipment is likely price prohibitive for desktop use, but you may be able to reduce the time a little with sidestepping that process either in your machine setup or with an external bit of lower cost hardware like and EDID emulator (e.g. https://www.extron.com/product/edid101h4kplus).

Re: Ask HN: Can you recommend an “instant-switch” Monitor? Does one exist?

#52

Post by modeless »

I bought one of the first GSync monitors many years ago (ASUS PG278Q ROG Swift) and it goes from sleep to displaying an image in just a fraction of a second. It's totally amazing, way faster than any other monitor I've ever seen, including newer GSync monitors. It only has one single input port though. I've never tried hooking it to a KVM, but I bet it would switch super fast.

Maybe try one of the first gen (2014) GSync monitors along with a DisplayPort KVM, if that can work for you. It's my understanding that the first gen GSync monitors all used the same monitor driver board that Nvidia made, so they probably behave similarly.

Honestly I didn't know how much I needed fast wakeup until I had it. It's a way better feature than GSync, yet monitor and TV reviewers generally ignore it completely. There are probably newer monitors with fast wakeup but it's impossible to know without testing. My TV takes like 8 seconds to even turn on its backlight and it's just ridiculous.

Re: Ask HN: Can you recommend an “instant-switch” Monitor? Does one exist?

#53

Post by bitwize »

OK, remember when modems were like EEEEEEEkRrRrRrRrRrRrRbaBONGbaBONG....

That was handshaking, and it was how modems figured out which speeds and protocols each other supported so they could figure out how fast to transfer data and how to encode it.

Monitors are kind of the same. There's handshaking that goes on each time you connect a monitor to a video source.

Like (and I'm totally making this up):

- Hi, I'm an AMD video card.

- Hi, I'm an LG monitor.

- You're a monitor? Great! I have some data I'd like to display. What resolutions, refresh rates, and color depths do you support?

- Well, I support 1920x1080x24bpp@60Hz, and 1600x900x24bpp@70Hz, and...

- Cool! I'd like to display at 1920x1200x24bpp@60Hz, please.

- Sure thing, hang about while I get that set up.

[Monitor CPU sets up whatever framebuffers, scalers, etc. are necessary to display at 1920x1200x24bpp@60Hz]

- Right then. Ready for your first frame.

- All right, first frame incoming...

Only then will you get your display. This can take a couple seconds.

Re: Ask HN: Can you recommend an “instant-switch” Monitor? Does one exist?

#54

Post by 3np »

Tangentially related: I find many monitors that look great on paper are a real annoyance when it comes to controls, be it brightness/contrast or input switching, making those 4s irrelevant in comparison.

Between recent models of Acer/Dell/Eizo/LG, I found Eizos to pose the least friction so far, with the LG (may be model-specific) a surprising worst. Reply to this comment with your anecdotes!

EDIT: To address the OP: Switching from an offline source to an active one is def smoother than you describe on my Eizo FlexScan EV series - I estimate it to <2s. The input switching is bearable enough that using the PbyP (two input sources split) is something I occasionally do, whereas with Dells it was just annoying enough to make me not bother.

Re: Ask HN: Can you recommend an “instant-switch” Monitor? Does one exist?

#55

Post by wasmitnetzen »

chmod775 wrote: post #13
_rs wrote: post #10

Earlier quoted context omitted.

What are the hardware limitations? Surely this is possible if there was investment and interest in making this work? Or do the protocols really not allow this?

In theory you could have a monitor that handles both signals all the time, buffering the output. Then it could switch immediately. It would however be more expensive, since you would need to duplicate at least some of the electronics within the monitor, a few of which also incur licensing/certification/patent/whatever fees.

Quite a few monitors support a Picture-in-Picture mode, so they are able to receive and decode two signals at the same time. But if that mode isn't enabled, they only receive one signal.

Re: Ask HN: Can you recommend an “instant-switch” Monitor? Does one exist?

#56

Post by bitwize »

Moru wrote: post #9

This has been annoying me since I first tried a PC after using Atari computers since they were a thing. No matter what monitor I use, it will take for ever to switch input port or just a simple change of resolution. I was used to be able to switch resolution several times per frame, you could make a game with low resolution and color on the upper 3/4 of the screen and have the stats in higher resolution 4 color mode…

One of the reasons why you could switch modes mid-frame is because the concept of a "video mode" is fundamentally different on a PC than on an Atari or Amiga. On a PC, ever since the EGA, the adapter can output at different horizontal and vertical scan rates and the monitor can adapt to the requested mode from the video card. That's why switching video modes takes a couple seconds and may involve a "click" or two. Upon mode switch, the monitor must resync to the new signal.

On the Atari and Amiga, the horizontal/vertical scan rates are constant; the only thing that changes is how scanout turns pixels in video memory into signals for the CRT.

Re: Ask HN: Can you recommend an “instant-switch” Monitor? Does one exist?

#57

Post by jwr »

I'm spending anywhere from 10 to 30 seconds every time I want to turn my monitor on. It's a game of fiddling with the buttons, trying to get it to wake up faster.

As an added bonus, the built-in firmware is terrible, and presents a "quick-switch" list of inputs which is different from the "normal" list of inputs, because… well, I don't know, just to make customers miserable, I guess.

Re: Ask HN: Can you recommend an “instant-switch” Monitor? Does one exist?

#58

Post by adrian_b »

brysonreece wrote: post #5

Unrelated: OP, how do you like the U2723QE? Been trying to decide on pulling the trigger on two of them recently.

I have its older version U2720Q and I am quite content with it, in a multi-monitor setup under Linux, using 30 bit per pixel, and also including a Dell loudspeaker system connected to U2720Q, used for audio via DisplayPort or HDMI.

I assume that the upgraded version U2723QE should be only better, with the possible exception of firmware bugs like what was mentioned by the other poster.

Re: Ask HN: Can you recommend an “instant-switch” Monitor? Does one exist?

#59

Post by netsharc »

bitwize wrote: post #53

OK, remember when modems were like EEEEEEEkRrRrRrRrRrRrRbaBONGbaBONG.... That was handshaking, and it was how modems figured out which speeds and protocols each other supported so they could figure out how fast to transfer data and how to encode it. Monitors are kind of the same. There's handshaking that goes on each time you connect a monitor to a video source. Like (and I'm totally making this up): - Hi, I'm an AMD…

I have an Asus monitor, it has DVI, HDMI, VGA. The HDMI has a quirk, I forget what, so I use a HDMI to DVI cable to connect my laptop to it. And when I switch sources away from DVI, the laptop doesn't think the 2nd display disappeared. So I don't think there's a handshake being done when switching back, because they were holding hands the whole time.

I think the quirk was, if I have something plugged into the VGA input, and the HDMI input goes to powersave mode, the monitor "helpfully" says, "Oh, no HDMI signal? Let me switch sources!"

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