Is VGA port hot-pluggable?

Question

In meetings, I often see people detaching the VGA connector from one running laptop and connecting it to another, while the projector is still on.

Is this 100% risk free, and OK by design of the VGA standard? If there's a risk involved in hot-plugging VGA, can it be removed by turning off or suspending either laptop, display, or both?

I see this being done all the time without causing disaster, so clearly I'm not interested in answers stating "we do it all the time, so it should be OK!".

I want to know if there's a risk - real or in theory - that something breaks when doing this.

EDIT: I did an internet search on the topic, and I never found a clear statement as to why it is safe or unsafe to hot swap VGA devices. The typical form is a forum question asking basically the same question as I did, and the following types of statements

• Yes it's hot swappable! I do it all the time!
• It involves some kind of risk, so don't do it!
• You're some kind of moron if you think there's a risk, so just do it!

But no explanation as to why it safe or not...

Joe Taylors answer below contains a link to a forum post and answers that basically give me the same statements as mentioned above. But again, no good explanation why.

So I looked for an actual manual for a projector, and found "Lenovo C500 Projector User’s Guide". It states on page 3-1:

Connecting devices

Computers and video devices can be connected to the projector at the same time. Check the user’s manual of the connecting device to confirm that it has the appropriate output connector.

[image]

Attention: As a safety precaution, disconnect all power to the projector and devices before making connections.

But again, no good explanation.

Answer 1

I would think the VGA standard don't say anything about hotswapping. So it is not designed to support hotswapping (like USB or firewire). But it usually works anyway (out of lazyness done so many times myself without problem), but the fact that it 'usually works' doesn't mean it's safe. So the manufacturers of those equipments can't say it is ok because there is no guarantee it is safe.

Also you could by accident get the pins (on the cable connector) onto the grounding (of the card connector) when connecting, might be a none issue but also not. USB -connector is designed to make this impossible.

Answer 2

A VGA port is 100% "Hot Pluggable".

Here's the same question and the answers to it. All support my statement. http://forums.overclockers.com.au/showthread.php?t=539941

The only problem with continually doing it is the continual wear and tear that you are putting on the pins. If you are careful then this isn't really an issue, but letting a ham fisted 4 year old do it might not be too advisable

Answer 3

easy to say yeah, fine,based on experience, but,

this guy says not a good idea if a different monitor. [1]

"Is it likely that a ... video card could be ruined ..." ---> VERY! Beyond just power issues you have drivers issues. When the computer boots it loads the drivers and sets the frequencies and voltages that the video card sends to the monitor that's attached to it. If you plug a monitor into a video card that didn't have a monitor (or had a different monitor) when the computer booted it's very likely the voltages and frequencies will be wrong for the monitor you are attaching. . The monitor could also be damaged.

[1] http://www.experts-exchange.com/Hardware/Desktops/Q_21945114.html