4

The DVI socket on my monitor is broken, so I decided to use the VGA socket.

I used a DVI-VGA adapter on my graphic card end, since it only has 2 DVI sockets.

It works but the resolution I can see from display property only goes up to 1600x1200, where I had 1920x1080 when using DVI.

My question is:

What is the maximum resolution supported, when going through a DVI-VGA adapter?

Is 1600x1200 the top, or something is wrong with my adapter/socket/cable/driver?

1
  • 1
    Chances are, you are not using an active converter (DVI-D to VGA), but rather a passive adaptor. This works because DVI-I sockets support both digital and analog signals, so your adapter is most likely simply taking the analog signal directly from the video card. DVI does not come into this.
    – Bob
    Jun 8, 2013 at 10:59

5 Answers 5

4

1600x1200 is the maximum supported resolution for UXVGA. The maximum support resolution for VGA is 640x480. The adapter is not relevant for resolution. It will be the output of the device. You can see an example of a UXGA cable below.

enter image description here

As you can see by the following picture of a VGA cable, they are almost identical (and WOW that is a huge picture...). These both use the HD15 connector.

enter image description here

The monitor you are using is UXGA compatible which can take resolutions from an HD15 all the way up to UXGA (highest rated interface for HD15 cables). This is why you can get a high resolution out of a VGA cable, they are compatible.

Please note that you can get a higher resolution using some tools, but it will look horrible. The following are supporting sources.

The following is a great chart that shows maximum support resolutions for many interfaces. enter image description here

8
  • 1
    Nice chart. I think there is a confusion over VGA as a standard and VGA as a cable. As the first post you linked to pointed out, VGA cable can go up to about 2048x1536. So is it the quality of the cable limiting the resolution? Or the adapter?
    – rokeyge
    Mar 31, 2011 at 12:03
  • The adapter poses no further limitations. Look at the output as being what you are using. When you use a DVI cable with a VGA/DVI adapter on the output, you are just making the DVI cable into a VGA. It might plug into a DVI port, but it only has the capabilities of a VGA. It is the interface that is limiting the resolution. In the link I first posted, I was trying to show that people look at VGA and UXGA as being the same (compatible). Most people look at a UXGA as being a VGA and don't really know of UXGA or a difference. Therefore, they state that VGA's max res is 1600X1200.
    – David
    Mar 31, 2011 at 13:09
  • Ok so I take it that VGA cable has HD15 connector, which allows the output to go up to the limit of UXGA (1600*1200)? People who post around the internet saying they have higher resolution are... wrong? lying?
    – rokeyge
    Mar 31, 2011 at 22:59
  • They could may not be lying. They may be using software that does something like overclocking you CPU. There is software that will make VGA go up to 1920X1080 (I have only heard of it, never used it). But as I said in my original answer, it is not supported for a reason, it looks horrible... And yes, to restate the answer again as it seemed like you asked the question in your last comment, UXGA's max resolution is 1600X1200. I'm not trying to mislead you, I am trying to help you understand the backbone of it. I am trying to help you understand why you are getting 1600X1200 out of a VGA.
    – David
    Apr 1, 2011 at 1:06
  • @David: You are the one confused. "UXGA" does not "support" a "maximum" resolution of 1600x1200. UXGA is 1600x1200 (whether over analog or digital connection). UXGA is simply a name for that resolution. There is another standard resolution at 1920x1200, that is "WUXGA" (the "W" means "wide"). No overclocking is needed and it does not look "terrible"; I run this res with an external analog monitor on my laptop all the time. "VGA" is in fact now a generic term for the analog signal format and does not usually refer to any particular resolution (it used to be 640x480, which is long obsolete). May 4, 2015 at 19:13
7

I own a 2048 x 1536 resolution monitor that has as its only input option a single VGA cable. It works very well with a standard ATI x800 video card. In theory, the resolution/amount of information that can be sent through any cable is mostly limited by the processing on either side of the cable. For instance, standard coax cable, used for antennas and SD television for years and installed in countless homes, can now be used to send multiple HD streams as well as internet signals by employing clever coding techniques on either side of the signal. This is also true of the power cables running through your house; using specially designed equipment, you can send internet and HD signals from one power outlet in your house to another using the existing cable. These are both examples of relatively low bandwidth 2 conductor cables carrying many times the amount of data they were originally intended to. A VGA cable has 15 conductors running through it, as well as a shield. A Cat5 cable that is often employed to send up to 4 streams of HD, total equivalent resolution of a whopping 7680 x 4320, has only 8 conductors! There are many other examples of this, particularly in the telecom industry, where it is necessary to find ways of using older existing cables to solve modern problems -if you're interested, just ask the humble fiber-optic cable, which recently passed a new landmark in transfer speeds exceeding its old one by 100 times!

I assure you that if you are having problems sending a 1920 x 1080 signal through a VGA cable, it is almost certainly an artificial limitation created either on the end of your PC, or your monitor(in this case it sounds like you monitor) - most likely due to the industries fascination with forcing people to migrate from one technology to another in the hopes of being the lucky one who gets to sell you something new! All of the standards in the technology we use are agreed upon at public international conventions for consortiums of electronics manufacturers. From year to year they dream up new versions of cables and encoding, and impose them on the industry in the following years. USB 2.0 or 3.0, HDMI 1.3 or 1.4, DVI-I or DVI-D, 720p or 1080p, MiniSD or MicroSD, they are all decided upon years before they are released, and roadmaps are drawn up to plan out their deployment. It's all fairly open and public actually - but collusion nonetheless in most cases to create a trickle of technology that forces people to constantly upgrade their equipment - in your case, by artificially restricting the VGA input on your monitor. It's called "planned obsolescence", and sadly you appear to be another victim! Don't worry - you're in good company(everyone)!

Interestingly, the telecom industry consortiums tend not to mandate too many changes requiring equipment and certainly cabling/infrastructure changes because the incurred costs would be paid by themselves! Thus, you end up with some of the examples above where the necessity to push the limits of existing cables resulted in some excellent innovation.

This may not have helped solve your problem, but I hope it helped explain it!

4

David's answer is wrong.

from Wikipedia
http://en.wikipedia.org/wiki/VGA_connector

The same VGA cable can be used with a variety of supported VGA resolutions, ranging from 640×400px @70 Hz (24 MHz of signal bandwidth) to 1280×1024px (SXGA) @85 Hz (160 MHz) and up to 2048×1536px (QXGA) @85 Hz (388 MHz).

VGA at here is NOT "the alias of screen resolution 640x480", but a connector's name, we also may called it D-sub connector by it's shape.

4
  • VGA is both. David's answer is only wrong by ommision. Note that that quote says the limit for QXGA is 2048x1536, but this says nothing about UXVGA, which is what David's talking about.
    – jpaugh
    Jun 8, 2013 at 12:36
  • 1
    In fact I can't understand any of the analysis made by David. There's many low-price "Full HD" monitors which only have VGA(D-sub) connectors and they work well on graphic cards supporting that resolution.
    – Vdragon
    Jun 9, 2013 at 12:47
  • I guess it depends on what version of the VGA standard is supported by the device. QXGA is the version listed by Wikipedia as high end. It's also listed in David's illustration. It's the next step up from UXGA, which is what he describes as being limited to 1600p.
    – jpaugh
    Jun 9, 2013 at 13:03
  • Maybe @David could explain..
    – jpaugh
    Jun 9, 2013 at 13:04
4

Just ran into a similar problem with a new, longer (10 meters) VGA-VGA cable. Both my TV set and laptop refused to put through it a signal higher than 1024x768, while a previous, shorter cable (about 2 meters long) supported 1920x1080 without any tricks. Upon a closer inspection, it turned out that one of pins inside one of plugs was bent. After a careful operation to straighten it, things returned to normal - full HD all right.

2

I use several Samsung capable 1920 x 1200, (WUXGA, (default resolution or “optimal”) monitors (Models 245BW, 2443 BWT, and a think a T240HD) all of which have a VGA , and a DVI connector. They are used in a multi-monitor workstation; using GeForce 9600GT boards (maximum capable digital display resolution is 2560 x 1600 (i.e., DVI); maximum (VGA is 2048 x 1536); per the GeForce.

http://www.geforce.com/hardware/desktop-gpus/geforce-9600-gt/specifications

I suspect the maximum resolution is determined by the quality of the video card (hardware on both the monitor and video card (matched impedances) ; and the quality of the cable); it goes into transmission line effects; the higher the frequency (resolution) ; the more pronounced the parasitic effects can become; also the length of the cable is a factor; Consult Smith Charts;

DVI cables “reject” noise better since this type of cable specifics twisted pair; this reject EMI better than just a shield ; I suspect DVI cables also have a shield in addition to twisted pairs; Consult Wiki for VGA spec and DVI spec it's probably stated in the specifications.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .