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Ask HN: Can you recommend an “instant-switch” Monitor? Does one exist?
21–30 of 185 posts
Re: Ask HN: Can you recommend an “instant-switch” Monitor? Does one exist?
#22You'll need a fancy KVM switch that does more than merely acting much like a physical switch would. Something like this should probably work: https://www.rextron.com/product-4K-2-Port-Full-Frame-PBP-KVM... Edit: The one above is merely the first one I found, not a recommendation. Be aware that such things may incur extra latency, since it's not just passing signals through, but rather processing them and repackaging…
There is no price listed for this switch. How much does it cost?
Re: Ask HN: Can you recommend an “instant-switch” Monitor? Does one exist?
#23Earlier quoted context omitted.
Why would you buffer? Monitors are capable of playing full-screen video, which implies the ability to update every pixel once per... 30hz? frame, doesn't it?
Because when you want instant switching you need to already have the data you want to display available the moment someone flips the switch. You can't just tell the computer that you're now interested in the display data of the other display - that would incur latency. You'll have to be receiving the information for the second display the entire time, storing it in what is commonly called a framebuffer, aka a bitmap…
It’s ok, I can wait 17ms for the next frame.
Re: Ask HN: Can you recommend an “instant-switch” Monitor? Does one exist?
#24Earlier quoted context omitted.
Why would you buffer? Monitors are capable of playing full-screen video, which implies the ability to update every pixel once per... 30hz? frame, doesn't it?
Because when you want instant switching you need to already have the data you want to display available the moment someone flips the switch. You can't just tell the computer that you're now interested in the display data of the other display - that would incur latency. You'll have to be receiving the information for the second display the entire time, storing it in what is commonly called a framebuffer, aka a bitmap…
Okay, I'm willing to wait 1/30th of a second while the screen gets its pixels; is that not an option? Or is there no way to request all pixels and it doesn't send them all every frame?
Re: Ask HN: Can you recommend an “instant-switch” Monitor? Does one exist?
#25Earlier quoted context omitted.
Because when you want instant switching you need to already have the data you want to display available the moment someone flips the switch. You can't just tell the computer that you're now interested in the display data of the other display - that would incur latency. You'll have to be receiving the information for the second display the entire time, storing it in what is commonly called a framebuffer, aka a bitmap…
It’s ok, I can wait 17ms for the next frame.
With basic analog you could set it up in a way where you would just wait for the next frame (or don't even wait that long), but with the new digital stuff there's bootstrapping/handshaking - whatever you want to call it. It's not so simple anymore.
Re: Ask HN: Can you recommend an “instant-switch” Monitor? Does one exist?
#26There are multiple input (5xHDMI) same output (1x HDMI) switches on the net, which feeds one input of the monitor and you can change the source on the adapter with a round robin button. It's almost instant. Another cool feature is whenever a new input source is detected it automatically feeds that to your monitor. I haven't seen the configuration you need, but if you can use adapters to convert each source to HDMI, it works like a charm. It's called an HDMI switch.
Re: Ask HN: Can you recommend an “instant-switch” Monitor? Does one exist?
#27There are hardware limitations that make what you're asking for impossible. Use software solutions if you actually need instant switch. But you probably don't.
What's impossible about it? I've seen devices in the past that can combine multiple HDMI signals into a single image (like picture-in-picture, or making one high-res display out of several lower-res video connections). And if you can do that, surely you can do instant switching just by toggling between "full screen input 1" and "full screen input 2" layouts.
Were any of these devices monitors? Were they cheap? Like it or not, price is a major factor.
On top of that, just look around - there is no perfect display,no matter how much one is willing to pay. Every single one has major drawbacks in certain areas.
Re: Ask HN: Can you recommend an “instant-switch” Monitor? Does one exist?
#28Earlier quoted context omitted.
Because when you want instant switching you need to already have the data you want to display available the moment someone flips the switch. You can't just tell the computer that you're now interested in the display data of the other display - that would incur latency. You'll have to be receiving the information for the second display the entire time, storing it in what is commonly called a framebuffer, aka a bitmap…
Okay, I'm willing to wait 1/30th of a second while the screen gets its pixels; is that not an option? Or is there no way to request all pixels and it doesn't send them all every frame?
I don't think I understand what you're saying.
I think you're concerned that because there's "buffers" there would be extra latency? There doesn't have to be.
Re: Ask HN: Can you recommend an “instant-switch” Monitor? Does one exist?
#29Earlier quoted context omitted.
Okay, I'm willing to wait 1/30th of a second while the screen gets its pixels; is that not an option? Or is there no way to request all pixels and it doesn't send them all every frame?
I don't think I understand what you're saying. I think you're concerned that because there's "buffers" there would be extra latency? There doesn't have to be.
That's what I'm asking. When the monitor is live, it can draw a complete screen ~30+ times every second, so why does it take more than 1/30th of a second to start from nothing? Then, I speculated that the only reason I could think of was if the graphics card doesn't actually send every pixel every frame, and there's no way for the monitor to request a full refresh.
Re: Ask HN: Can you recommend an “instant-switch” Monitor? Does one exist?
#30Yeah would be nice to be able to alt-tab between monitors (or I should say: sources). I never understood why it is so slow. I have a somewhat older Samsung TV and I even have to cycle all the inputs (8?) to arrive a the correct one and it takes 1-3 sec on every input before I can get to the next. Absolutely maddening. But I guess manufacturers were too busy making 3D a thing and then "curved". Maybe they can now decide to fix some basics?