KVM switchboxes

[LadyCrimson]

I like KVM switchboxes. Obviously, monitors are coming with no VGA these days, so I'll need a new one soon for when I feel like having/using two PC's on at once. Which isn't often these days but I still like having the option there.

I have no clue what to look for, but I do know non-VGA ones seem pretty darn expensive for some unfathomable reason.   Could you get one that will KVM switch between a VGA and a DVI-D one? Or is that just not possible and you always have to have the monitors be all the same.

 

Anyone have one to recommend?

[Gorgon]

Isn't everything HDMI these days. My card has four I think, some ridiculous number, probably for eyefinity. I don't understand what you need a switchbox for when you are running two PC, but I'm probably stupid. Do you have just one monitor ?

[LadyCrimson]

My understanding is that hi-res monitors are DVI-D. Some monitors require it to get higher than 1920x1080 resolutions.

 

I like them for when you have 2 (or more) PC's and 2 (or more) monitors and you don't want two+ keyboards and mice. I suppose not many use them anymore ...

[AwesomeOcelot]

I don't know why they're so expensive, doesn't make much sense considering switches for just the video are not expensive, which is an option, keep your old KVM and get a video switch, less convenience but much cheaper. People don't run multiple desktops like they used to, laptops and tablets have their own screen and interface, there are options like VM for many tasks, if they do they can interface with it through VNC/CLI over a network. Synergy/Mouse Without Borders/Multiplicity allow Mouse+KB control over a network.

 

I think HDMI is just as popular as DVI-D now, and DVI-D Dual Link is not as popular, so if you want high resolution then go with HDMI or DisplayPort. Most KVM for HDMI and DisplayPort only support 1600p (HDMI 1.3 and DisplayPort 1.1), not the maximum resolutions, as they're older than the latest standards. If you're looking for future proofing with 4K support you'd need HDMI 2.0 (in the near future) or DisplayPort 1.2 as they support 4K at 60hz.

 

My understanding is that hi-res monitors are DVI-D. Some monitors require it to get higher than 1920x1080 resolutions.

DVI-D Dual Link has the same max resolution as HDMI 1.4. HDMI 1.4 supports 2160p@30 (4K Ultra HD), HDMI 1.3 1600p@75. High performance monitors are usually DisplayPort, because it's usually ahead of HDMI, it supports 2160p@60, it'll be the first to 4320p. So far DVI-D/HDMI/DisplayPort are compatible with each other.

[Janmanden]

Actually, i used to have a KVM switch too and used those VGA-DVI adapters, that sometimes are included in the box with gfx cards, without issues, but it was a long time age, relatively speaking.

[AwesomeOcelot]

DVI-I contains the pins that carry the VGA signal, so you can use a simple adapter if the device supports DVI-I. DVI-D doesn't have those pins, you have to get a more expensive converter, you can get VGA to HDMI/DisplayPort adapters too. Modern monitors don't do well with VGA signals, and converters generally don't do a great job. Digital standards like HDMI/DisplayPort/DVI don't suffer from bad cables or interference.

Edited April 7, 2014 by AwesomeOcelot

[Janmanden]

Damn. I missed the D, but they should be compatible still at the lowest level with a possibly increased loss and interference. DVI-D has the same pins as DVI-I and then some extra to produce a better signal and higher res. Of course if that's not acceptable, then you need to do what AwesomeOcelot suggest, I guess. Also, it wouldn't really surprise me if some manufactures dropped the ball on backwards compatibility. Checking is always good.

[AwesomeOcelot]

DVI-D has the same pins as DVI-I and then some extra to produce a better signal and higher res.

Nope, DVI-D is not compatible with VGA. A DVI-I has 4 extra pins to the left (5 in total), DVI-D has 1 pin, DVI-A has 5. DVI-I is basically both a DVI-A and DVI-D, DVI-I has the pins to support either. DVI-A supports a VGA signal, therefore so does DVI-I. Even if it had the same number of pins, DVI-D devices would only expect digital signals, they wouldn't have the necessary hardware for analogue signals.

 

DVI-I dual link or DVI-D dual link have 6 extra pins in the middle of the right bank. Those are for higher resolution, dual link has no benefit if using a DVI-I passive adapter to VGA.

 

I've never seen a monitor using the DVI-I or DVI-A standard input in any case. I've never seen the DVI-A standard at all, I don't think it was ever popular. DVI-I was used for outputs because it saves space, you could have a digital DVI-D output or a VGA output from the graphics card, with one DVI-I to VGA passive adapter, most of my cards I've bought had 2 DVI-I outputs, all of them from 2000 to present. So if your monitor is DVI, it's safe to assume it's DVI-D, if it accepts analogue signals it's through VGA (D-Sub) or other kind of analogue port (e.g. composite, S-Video, component).

Edited April 9, 2014 by AwesomeOcelot

[Mor]

I like them for when you have 2 (or more) PC's and 2 (or more) monitors and you don't want two+ keyboards and mice. I suppose not many use them anymore ...

I don't think many used KVMs, ever. I honestly can't think of why would I need to use a two PC setup permanently at home. KVMs are best suited for server rooms, technicians labs or other environment where two separate computers are necessary or mandated( e.g. work, presentation rooms or army), but now you can usually run a virtual desktop or get fancy with extending your work into two screens. :/

[Mor]

Btw:

I don't know why they're so expensive, doesn't make much sense considering switches for just the video are not expensive, which is an option, keep your old KVM and get a video switch, less convenience but much cheaper.

Btw, by display only I assume you mean something like this old passive VGA switch:

 

 

 

 

While the more expensive types are active switches(comes with power supply) which create feedback on all ports to avoid the annoying waiting period when you switch.