DVI quality with a VGA cable?

[PitViper]

The LCD monitor I’m looking to purchase comes with a VGA cable but no DVI cable. (It has both DVI and VGA inputs.) However, my video card came with a DVI to VGA adapter and I have access to a second DVI to VGA adapter.

Will the quality of a VGA cable with the adapters be the same as a dedicated DVI cable?

[Jeffbx]

Nope - the DVI signal gives a much nicer pic than VGA. It would be worth the few bucks to get yourself a DVI cable.

[DarkFury]

Anytime you go from a "digital" to an "analog" signal (or vice versa)... you generally don't get "improved" or equal quality... however the picture quality from Digital to Analog might be slightly better than just going straight analog.

[ski]

Nope - the DVI signal gives a much nicer pic than VGA. It would be worth the few bucks to get yourself a DVI cable.
It won't be a few bucks at your local retailers unfortunately.

$60 for a DVI cable at Best Buy! I recommend shopping online for them :)

[CynJon]

It won't be a few bucks at your local retailers unfortunately.

$60 for a DVI cable at Best Buy! I recommend shopping online for them :)

Under $10 shipped on Fleabay (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=73387&item=5784283025&rd=1)...

[PitViper]

I guess I didn’t make my question clear. I am planning to use the DVI-out from the video card to the DVI-in on the monitor. My question was on the signal quality of using a standard VGA cable with a DVI to VGA adapter on each end. Some video cards ship with two such adapters, so I assume you can use a VGA cable as a DVI cable if equipped which the adapters.

But will such a cable be inferior to a dedicated DVI cable? Perhaps it's not worth taking the chance.

XFX Geforce 6800 shown shipped with two DVI to VGA adapters (http://www.newegg.com/Product/ShowImage.asp?image=14-150-068-01.JPG,14-150-068-02.JPG,14-150-068-03.JPG,14-150-068-04.JPG,14-150-068-05.JPG&CurImage=14-150-068-04.JPG&Description=XFX%20PVT40KND%20Geforce%206800%20128MB%20DDR%20AGP%204X/8X%20Video%20Card%20-%20Retail)

Update: I see the XFX 6800 has two DVI-out ports, hence the two adapters. My PNY 6800 only has one DVI-out so it only shipped with one adapter. But the question still remains, can the VGA cable equipped with two adapters be used as a DVI cable, or won’t the pin-outs be workable?

[DarkFury]

I guess I didn’t make my question clear. I am planning to use the DVI-out from the video card to the DVI-in on the monitor. My question was on the signal quality of using a standard VGA cable with a DVI to VGA adapter on each end. Some video cards ship with two such adapters, so I assume you can use a VGA cable as a DVI cable if equipped which the adapters.

But will such a cable be inferior to a dedicated DVI cable? Perhaps it's not worth taking the chance.

XFX Geforce 6800 shown shipped with two DVI to VGA adapters (http://www.newegg.com/Product/ShowImage.asp?image=14-150-068-01.JPG,14-150-068-02.JPG,14-150-068-03.JPG,14-150-068-04.JPG,14-150-068-05.JPG&CurImage=14-150-068-04.JPG&Description=XFX%20PVT40KND%20Geforce%206800%20128MB%20DDR%20AGP%204X/8X%20Video%20Card%20-%20Retail)

Update: I see the XFX 6800 has two DVI-out ports, hence the two adapters. My PNY 6800 only has one DVI-out so it only shipped with one adapter. But the question still remains, can the VGA cable equipped with two adapters be used as a DVI cable, or won’t the pin-outs be workable?
Honestly, I don't think that the analog with 2 adapters is a good idea to get "DVI quality" without the actual cable.

[Daversinger]

There are fewer pins in the vga cable than there are in a dvi cable, I’m not exactly sure if the monitor uses all those pins, but pins are pins its just how the signal sent through them is interpreted which makes the difference. But, i would highly suggest you just buy a dvi cable if you are that worried about the quality. Dude 10$ thats it, I may have an extra laying around.. :cool:

[Jeffbx]

But will such a cable be inferior to a dedicated DVI cable? Perhaps it's not worth taking the chance.


Yes, it will be inferior connection - you have a DAC and an ADC going on - digital to analog conversion, then analog to digital conversion. Anytime you degrade the signal down to analog, that's the quality of the connection you'll see. It should work fine, but you'll certainly get a better connection with a straight DVI cable.

And as Ski mentioned, DON'T buy cables from your friendly local retailer - they mark those stupid things up about 800%. You should be able to pick one up online for no more than $20.

[DarkFury]

Yes, it will be inferior connection - you have a DAC and an ADC going on - digital to analog conversion, then analog to digital conversion. Anytime you degrade the signal down to analog, that's the quality of the connection you'll see. It should work fine, but you'll certainly get a better connection with a straight DVI cable.


Hmmmm... didn't I kinda say something like that earlier? :shrug: :D