Both VGA and DVI connectors transmit video signals from a source device to a display device. Even though they work pretty much the same way, at least from a user’s point of view, there are a couple of differences that set them apart — aside from the fact that VGA carries analog signals while DVI carries digital signals.
This post will explore these differences further as we seek to find out which is better: VGA or DVI.
What Is VGA?
First used in 1980, VGA (Video Graphics Array) can be easily identified by its blue connector and port. VGA connectors transmit analog signals from a source device like a computer to a display device like a monitor or TV.
It was created to be used in devices that had a graphics card, so you will often see VGA ports on TV sets, projectors, computers, laptops, and other devices.
VGA works pretty much like other video transfer cables. It receives the analog signals from the source and transfers them to another device. The signals may vary greatly in quality depending on the quality of the cable as well as the length.
That notwithstanding, it is possible to achieve high-resolution pictures because VGA is capable of transmitting signals at high frequencies.
The VGA connector has 15 pins and goes by many names: RGB connector, HD 5, HDB-5, D15, DB-15, or HD-15.
Despite the many identities, a VGA connector is only available as one type. It is, however, available in different sizes, from a small size of 0.75 feet up to 30 feet.
Additionally, the cables are either double-shielded or triple-shielded and come with a plenum cable jacket.
What Is DVI?
DVI is pretty much VGA’s successor. It was created to resolve some of the limitations that VGA had. DVI, as already mentioned, carries digital video signals from the source to the display device.
If you look at the back of your computer, you will most likely see multiple DVI ports. All these ports have different functions.
There is the DVI-D, which can be a single-link or a dual-link, and carries digital signals only.
Single-link means that it supports resolutions of up to 1920 by 1200 at 60 Hz, while a dual-link means it supports resolutions of up to 2560 x 1600 at 60 Hz.
Single-link uses a single 165 MHz transmitter to support the resolutions, while a dual-link uses two transmitters and hence is more powerful since it provides data transmission at twice the rate.
Single-link is considered ideal for transmitting data to monitors, while dual-link is considered the best choice for large screens.
DVI-D is perhaps the most popular type of DVI.
Secondly, there is the DVI-I, which transmits both the digital and analog signals and can also be a single- or dual-link. It, however, does not convert signals; it either transmits analog signals all the way through or digital signals all the way through.
Lastly, there is the DVI-A, which only transfers analog signals. This is more similar to VGA and is often used to connect CRT monitors since they use analog technology. Digital to analog conversion can occur with this format connector.
Is VGA or DVI Better: A Comparison
Now let’s compare the two side by side to see how each is different. This is the ultimate way to decide which is better.
How they work
Ideally, both connectors have a similar operation mechanism. They both have male connectors that are plugged into the female connectors of the device’s ports. The signals are then transmitted from the source’s ports via the connectors to the display device, which is the destination.
While both operate pretty much the same way, the difference comes when you have digital devices and only have a VGA cable. Conversion has to occur between the source and the connector, and similarly between the connector and the display device.
This is what we mean.
Suppose you want to connect your computer to your HDTV, but you only have a VGA cable, this is what will happen:
The computer’s digital signals will be received by the VGA connector, but since the VGA can only transmit analog signals, it will have to convert the digital signals to analog signals, after which they will start their journey to your HDTV.
Once they reach the other end of the VGA, the TV’s port cannot receive analog signals, so again, conversion from analog to digital will take place. Once converted, the TV will receive the digital signals and then display them.
This conversion from digital to analog and back to digital causes the signals to degrade, hence the lower picture quality.
DVI, on the other hand, does not require any conversion since they only transmit digital signals.
Quality of signals
Since it’s the newest technology of the two, DVI offers better signal quality than VGA. This is, however, subject to the quality of the cable as well as the length.
A low-quality cable, whether VGA or DVI, is prone to crosstalk and other electrical disturbances. This happens when wires adjacent to each other in a cable induce unwanted currents. However, VGA cables are way more susceptible than DVI cables.
Similarly, longer VGA cables are also more likely to experience signal interferences than DVI.
Whether using VGA or DVI, always using premium quality cables with thicker insulation is the best practice.
In addition to being a newer technology, DVI is built for a cleaner, sharper transmission, hence a cleaner and sharper display. On the other hand, VGA is considered to offer a lower-quality display because of how susceptible they are to noise and the fact that they are an old-school technology.
Neither the VGA nor DVI connectors are capable of transmitting audio. So, you have to connect a separate audio cable to your TV or speakers should you need to listen to audio.
|Signal type||Digital RGB||Analog RGB|
|Display quality||Cleaner, faster, and more precise
Designed for higher resolutions
|Lower picture quality
Designed for lower resolutions
|Compatibility||HDMI and VGA||VGA-to-DVI and VGA-to-HDMI|
|Signal quality||Resistant to noise||Susceptible to noise/interferences
Degrades because of digital to analog conversion and back
|Connector||White/black connector, 29 pins||Blue connector, 15 pins|
Perhaps the biggest difference between these two technologies is that VGA is old-school and hence transmits analog signals. Whereas DVI is digital and hence transmits digital signals. Aside from that, the other differences may not be apparent unless you run both connections concurrently to see the difference.
But the truth is, DVI will always be better than VGA.
That said, we recommend you buy a DVI if all your devices are digital. While you can still use a VGA, the signal interference and degradation due to conversion is honestly not worth it.
If you have a mix of digital and analog devices, consider getting a VGA. This is especially true if you have an old CRT monitor, since they don’t have any digital ports.
An even bigger reason to choose DVI is that VGA is slowly being phased out, as more and more people are moving towards digital devices. So, unless you want to incur additional costs of buying DVI/VGA converters, DVI is your best bet.