VGA to DVI-D?

[JorgeA]

Hello,

I'm looking to connect the VGA port on a computer to the 24+1 DVI port on an LCD monitor, but my shopping research on Amazon and Newegg has left me more confused than enlightened. Seems to be a great lack of clarity out there. (It doesn't help matters that there are so many different types of DVI plugs.) Not only do the search functions turn up many more "DVI to VGA" cables and adapters than "VGA to DVI" items, but I get contradictory information as to whether these thingies can go both ways.

Can anybody recommend a modestly priced cable (brand name would help), adapter, or connector of any kind that will do what I need it to do? Or is this a pipe dream?

I have a VGA cable, so I could use a theoretical "VGA female to DVI male" adapter. Or alternatively, a theoretical cable (with no adapter) would run "VGA male to DVI male."

This is to connect a second PC to the same existing monitor. I'd then use the Input Select button on the monitor to go back and forth between PC displays, just like our TV can switch from antenna, cable, VCR, and DVD inputs.

Another route would be to use a KVM switch, but my father has one of these and it's a real PITA to use, very finicky and highly unreliable -- half the time, he ends up having to reboot one computer or the other after trying to switch inputs. So I'd like to avoid that approach if possible.

Thanks in advance for filling me in on this. Keeping my fingers crossed...

--JorgeA

[Kelsenellenelvian]

http://www.newegg.com/Product/Product.aspx?Item=N82E16812267001

$6 bucks!!!! (I use some of these at home)

[JorgeA]

Kelsenellenelvian,

Thanks for the link, I checked it out.

Two questions, if you don't mind. First, just to make sure -- you got this adapter to work when running a VGA output from the computer to a DVI input on the monitor? I've heard conflicting things from different salesmen on this point. One guy told me that these things work in only one direction (i.e., the opposite of what I need), and the other says that they can go either way.

Second, take a look at the user feedback dated 7/9/11, who states categorically that, "it will NOT convert between a DVI-D & VGA." And actually, looking closely at the picture from the DVI end, it looks like it's the 24+5 variety (DVI-I, I think). Too many prongs for my monitor's port, which lacks the openings for the four pins around the wide blade on the left in the picture.

What do you think?

--JorgeA

[Kelsenellenelvian]

Ah Yes I have 2 of those ones you are describing.

Lemme go shop around.

[gUiTaR_mIkE]

This can be very confusing, I went thru it a while back, this is what I took away:

Your VGA source is analog, your DVI port may be digital only (DVI-D), analog only (DVI-A), or digital and analog (DVI-I) depending on your monitor. The DVI-D has no connectors for the analog pins therefore will not work with an analog source (digital and analog cannot communicate). If your monitor has a group of 4 pins it will accept an analog signal.

You may also have a single link or a dual link, check the number of pins. The DVI-I interface has a wider horizontal blade pin between the group of 4 pins.

The moral of the story is...

... if your monitor has a group of 4 pins (with a wide blade) and about 18 additional pins = DVI-I single link

... if your monitor has a group of 4 pins (with a wide blade) and about 24 additional pins = DVI-I dual link

... if your monitor has a narrow blade (no group of 4 pins) and about 18 additional pins = DVI-D single link

... if your monitor has a narrow blade (no group of 4 pins) and about 24 additional pins = DVI-D dual link

I doubt your monitor uses DVI-A, it is a strange connector, your monitor documentation should spell all this out.

Btw, take this with a grain of salt, it's been a while since I looked into DVI, some things may have changed

[Kelsenellenelvian]

Edit mike may be right:

http://www.newegg.com/Product/Product.aspx?Item=N82E16812119261

I am not to keen on dvi-d (&*)^%$

But I will still dig around and see if I can help you.

Re EDIT:

http://en.wikipedia.org/wiki/Digital_Visual_Interface

Mike is right.... If your monitor is dvi-d then you are out of the choice of using a simple adapter.

Edited July 24, 2011 by Kelsenellenelvian

[JorgeA]

This can be very confusing, I went thru it a while back, this is what I took away:

Your VGA source is analog, your DVI port may be digital only (DVI-D), analog only (DVI-A), or digital and analog (DVI-I) depending on your monitor. The DVI-D has no connectors for the analog pins therefore will not work with an analog source (digital and analog cannot communicate). If your monitor has a group of 4 pins it will accept an analog signal.

You may also have a single link or a dual link, check the number of pins. The DVI-I interface has a wider horizontal blade pin between the group of 4 pins.

The moral of the story is...

... if your monitor has a group of 4 pins (with a wide blade) and about 18 additional pins = DVI-I single link

... if your monitor has a group of 4 pins (with a wide blade) and about 24 additional pins = DVI-I dual link

... if your monitor has a narrow blade (no group of 4 pins) and about 18 additional pins = DVI-D single link

... if your monitor has a narrow blade (no group of 4 pins) and about 24 additional pins = DVI-D dual link

I doubt your monitor uses DVI-A, it is a strange connector, your monitor documentation should spell all this out.

Btw, take this with a grain of salt, it's been a while since I looked into DVI, some things may have changed

Mike,

It may have been a while, but your memory is perfect! You got it exactly right -- your description of DVI-D dual link matches what my monitor has.

Looks like my choices are more limited, then.

--JorgeA

[JorgeA]

Edit mike may be right:

http://www.newegg.com/Product/Product.aspx?Item=N82E16812119261

I am not to keen on dvi-d (&*)^%$

But I will still dig around and see if I can help you.

Re EDIT:

http://en.wikipedia.org/wiki/Digital_Visual_Interface

Mike is right.... If your monitor is dvi-d then you are out of the choice of using a simple adapter.

Kelsenellenelvian,

Yup, Mike is definitely right and I'm going to have to spend a bit more to get this idea to work.

Last night I found this interesting page that tells you what you need to get so as to connect one type of output to another type of input (scroll down to 3a). I'd need two different cables and an adapter to go between them. Fortunately the adapter isn't the $200 kind that I've heard of.

I guess that another way would be to buy an inexpensive video card with a DVI port. Then I could connect the PC directly to the monitor, what do you think?

Thanks very much for looking into all this!

--JorgeA

Edited July 24, 2011 by JorgeA

[gUiTaR_mIkE]

I guess that another way would be to buy an inexpensive video card with a DVI port. Then I could connect the PC directly to the monitor, what do you think?

IMO this is the way to go, find a video card that works in the available slot in your PC and matches the 'connector type', 'resolutions (usually recommended)', and 'refresh rates' of your monitor. Then buy the cable to match. Also, check the specs on the new card and make sure you have enough left in your power supply to power it, don't forget about the power connector if needed.

This is also a good time to think ahead, you may want to run dual monitors (one PC) down the road - who knows - DVI x2.

Beware DVI-D cables can be thick and don't like a tight radius so make sure you can run the cable with only a slight curve into the card and monitor - you'll see when you get the cable

Anyway, enjoy your new setup, seems like a nice monitor.

[JorgeA]

I guess that another way would be to buy an inexpensive video card with a DVI port. Then I could connect the PC directly to the monitor, what do you think?

IMO this is the way to go, find a video card that works in the available slot in your PC and matches the 'connector type', 'resolutions (usually recommended)', and 'refresh rates' of your monitor. Then buy the cable to match. Also, check the specs on the new card and make sure you have enough left in your power supply to power it, don't forget about the power connector if needed.

This is also a good time to think ahead, you may want to run dual monitors (one PC) down the road - who knows - DVI x2.

Beware DVI-D cables can be thick and don't like a tight radius so make sure you can run the cable with only a slight curve into the card and monitor - you'll see when you get the cable

Anyway, enjoy your new setup, seems like a nice monitor.

Hi Mike,

Thanks for the tips -- especially about the thick DVI-D cable, this will help me plan the layout of the components. Looks like I have some shopping to do!

In the meantime, I'll switch the VGA cable back and forth between computers as needed. Will make sure to turn the monitor off before unplugging from one PC.

--JorgeA