DVI-D vs VGA cable: differences?

Started Mar 5, 2012 | Discussions
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Rebel04 Forum Member • Posts: 82
DVI-D vs VGA cable: differences?

Hi all,

I have a CRT monitor and now I want to buy a new monitor: Dell U2412M (16:10 res.1920x1200), this monitor has a VGA and a DVI-D output.

My pc has an integrated graphics card (Nvidia GeForce 6150SE) with only the VGA output (with the maximum resolution of 1920x1440).

I don't play games, watch HD video on my computer, I just use it for internet and for photo editing (Photoshop CS5).

My question is: is there a difference between VGA and DVI cable? I.e. in the colours, brightness, etc. (I would calibrate the monitor with the new spyder4 pro). As said I'm interested specifically in responses relating to photo editing. Or should I buy a new computer with the DVI output?

Thanks

Bob Collette Veteran Member • Posts: 3,830
Re: DVI-D vs VGA cable: differences?

The primary difference between DVI and VGA is that DVI is digital whereas VGA is analog. Since the computer itself is digital, DVI gives the "cleanest" signal, since the data that is transferred between computer & monitor remains in the digital domain. However, with VGA, the process that happens is as follows:

.................. Computer .................................................. Monitor

Digital data converted to Analog via DAC --> Analog data converted to Digital via ADC

Because of the digital to analog and analog to digital conversions that have to take place with a VGA connection, you run a real risk of introducing noise into the image. How much depends upon the quality of the video card & monitor conversion electronics.

I would suggest that you try it with the VGA connection and see how it looks. If it looks relatively "clean" (little noise & interference), you're all set. If you see noise or interference, you likely would benefit from a DVI connection. You likely don't have to buy a new computer. Most computers with built-in video will accept a discrete video card. In fact, I just purchased a new low-end video card (Gigabyte GeForce 210, 1GB video card with VGA, DVI, and HDMI connectors) for my backup computer for $10 after rebate today. You don't need an expensive video card for photographic work.

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Eric Carlson
Eric Carlson Veteran Member • Posts: 6,474
Re: DVI-D vs VGA cable: differences?

Another potential issue with using analog is that the pixels won't be in perfect alignment on the screen. With digital, when using the monitor's native resolution, you get a perfect 1 to 1 pixel mapping, so the display is as crisp as it is able to be. Some monitors do a better job than others of getting the analog signal to display accurately.

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Eric Carlson
Eric Carlson Veteran Member • Posts: 6,474
Re: DVI-D vs VGA cable: differences?

Rebel04 wrote:

...this monitor has a VGA and a DVI-D output .

FYI: Minor correction, not that it is relevant to your issue, but monitors have inputs . Video cards have outputs . The video signal goes out of the computer via the output , and into the input on the monitor. For some reason, I often see people saying one when the mean the other.

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DUMB4SS Regular Member • Posts: 470
If you upgrade your video card

Check the internal connections first, so you know what card to get.
PCI, AGP, PCI-E

(Link to image from Toms computing guide)

ShakinEakin New Member • Posts: 7
Re: DVI-D vs VGA cable: differences?

Basically, it's VHS vs. DVD quality. Anything larger then 19" you will notice a difference. If you try to use VGA on the 24" monitor, it will appear fuzzy. After a few hours, your eye's will feel it.

Using DVI will make the image crystal clear. With such a nice monitor, the best thing is to buy a new video card.

Since you are not doing gaming, even an entry level DVI card will work. They are very inexpensive and will provide a much better experience. Newegg, Amazon, etc. are good places.

Have fun with your nice new display. It should prove to be a delight from your current monitor.

Rebel04 OP Forum Member • Posts: 82
Re: DVI-D vs VGA cable: differences?

Thanx!! I just bought a new video card via amazon (fortunately my motherboard has a pci-express 16x slot !) so now I can use the digital signal with my new monitor

thanx again to all!

Glen Barrington
Glen Barrington Forum Pro • Posts: 16,685
Re: If you upgrade your video card

Now THIS is useful information, thank you!

DUMB4SS wrote:

Check the internal connections first, so you know what card to get.
PCI, AGP, PCI-E

(Link to image from Toms computing guide)

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johnashdown123 New Member • Posts: 3
Re: DVI-D vs VGA cable: differences?
2

VGA is analog and DVI is digital. You will get better image
quality with DVI. You can either buy a new computer with DVI connector
is use a VGA to DVI-D converter. Please not cheap cables and adpaters
will not work if you decide to go with the converter. You will need a
true converter that does analog to digital signal conversion.

aethelbuz New Member • Posts: 5
Re: DVI-D vs VGA cable: differences?

VGA is analog and DVI is digital. You will get better video quality with digital signal. Just depends on what applications are you planning and what type of video quality is needed.

Jen Yates Senior Member • Posts: 1,413
Re: DVI-D vs VGA cable: differences?

Nice first post. Answered a seven month old question with an answer that duplicates what others have already said.

Supr X
Supr X Veteran Member • Posts: 4,956
Re: DVI-D vs VGA cable: differences?

Jen Yates wrote:

Nice first post. Answered a seven month old question with an answer that duplicates what others have already said.

Heh. So much for reading the entire thread . . .

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aethelbuz New Member • Posts: 5
Re: DVI-D vs VGA cable: differences?

VGA is analog and DVI is digital. You will get better image quality of you use digital DVI port. There are some applications where you need to use DVI-D to VGA or VGA to DVI-D converters but that is not the case as far as your application goes.

BobSC Veteran Member • Posts: 3,664
Re: DVI-D vs VGA cable: differences?

aethelbuz wrote:

VGA is analog and DVI is digital. You will get better image quality of you use digital DVI port. There are some applications where you need to use DVI-D to VGA or VGA to DVI-D converters but that is not the case as far as your application goes.

I don't notice a whit of difference. Maybe there is some difference you could measure with some kind of sophisticated measuring device, but I sure can't see it. My monitor and my video card both had both VGA and DVI so I spent time switching between them. Couldn't tell which was which without the HUD spelling it out.

Eric Carlson
Eric Carlson Veteran Member • Posts: 6,474
Re: DVI-D vs VGA cable: differences?

BobSC wrote:

I don't notice a whit of difference.

From many recent reports I've seen from random posters, it seems VGA often works pretty well with LCD monitors these days. I've seen older LCD monitors that did a bad job of properly aligning the analog image on the screen, but I have 2 identical monitors on my work PC (my left and right side monitors -- the center monitor is larger), and one is connected via DVI and the other via VGA, and as long as the monitor on VGA is properly auto-aligned, it looks identical to the monitor on DVI.

So there is a good possibility VGA will look fine, but it isn't guaranteed.

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BobSC Veteran Member • Posts: 3,664
Re: DVI-D vs VGA cable: differences?

Eric Carlson wrote:

BobSC wrote:

I don't notice a whit of difference.

From many recent reports I've seen from random posters, it seems VGA often works pretty well with LCD monitors these days. I've seen older LCD monitors that did a bad job of properly aligning the analog image on the screen, but I have 2 identical monitors on my work PC (my left and right side monitors -- the center monitor is larger), and one is connected via DVI and the other via VGA, and as long as the monitor on VGA is properly auto-aligned, it looks identical to the monitor on DVI.

So there is a good possibility VGA will look fine, but it isn't guaranteed.

Here's another factor -- When we got a new PC at work we hooked up the new monitor with a VGA cable and it looked terrible. Later that day a new video card arrived, and the same monitor with the same VGA cable looked awesome. The built in video just wasn't good. It could be that some people attribute the improved visuals with a change in cable when it's really due to inferior graphics hardware. But maybe that's what you were saying


Eddaweaver Senior Member • Posts: 2,231
Re: DVI-D vs VGA cable: differences?

VGA quality varies significantly. In the past nearly all video cards not made by Matrox had poor to atrocious VGA quality.

DVI will be superior to VGA on an LCD monitor although some people won't notice the difference.

There is seldom a reason to buy a whole "new computer" to get DVI / HDMI / Displayport when buying a new videocard would do

Eric Carlson
Eric Carlson Veteran Member • Posts: 6,474
Re: DVI-D vs VGA cable: differences?

BobSC wrote:

Here's another factor -- When we got a new PC at work we hooked up the new monitor with a VGA cable and it looked terrible. Later that day a new video card arrived, and the same monitor with the same VGA cable looked awesome. The built in video just wasn't good. It could be that some people attribute the improved visuals with a change in cable when it's really due to inferior graphics hardware. But maybe that's what you were saying

It is possible that the many recent reports of good VGA quality on LCD monitors is in large part due to improved VGA signal quality out of modern video cards.

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MisterBG Veteran Member • Posts: 5,823
Re: DVI-D vs VGA cable: differences?

I have an LG 22" monitor with both VGA and DVI connections, along with an ATI graphics card which has VGA and DVI outputs.

I have carefully examined the display using the VGA and then the DVI connection, and can see absolutely no difference between them.

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offroadcmpr Forum Member • Posts: 75
Re: DVI-D vs VGA cable: differences?

I have a 23 inch 1080 monitor that accepts DVI and VGA. While I had my laptop I used VGA, I also briefly used VGA on my desktop before switching to DVI. I can't say that I noticed a single difference. Not sure if it is because they have gotten better over time, or if it is because I have a cheap monitor with a TN panel. Maybe it would be easier to spot differences on a nicer display.

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