Last Updated on October 5, 2019 by Dave Farquhar
New computer, old monitor: I see questions fairly frequently about using a new computer and older monitor together. More often than not, it’s possible to do, but you may need to know where to look for the cables and adapters you’ll need.
Here’s some help.
Mismatched brands
Mixing brands generally isn’t a problem. Just as anyone’s Blu-Ray player will connect to anyone else’s television, you can connect an Emachines monitor to an HP, Dell, Lenovo, Asus, Acer, or other brand of computer or vice versa. You may need an adapter to make it happen, and you may or may not be happy with the results depending on how old the monitor is, but as long as your monitor was made after about mid 1994, it can be done. And even a lot of monitors made between 1987 and 1994 work with new stuff too.
The important thing to remember is if I can make 30-year-old stuff work together with new stuff, we can make 10-year-old stuff work together with new stuff too.
Displayport vs. DVI vs. HDMI vs. VGA
Displayport is the new standard for digital, high-resolution displays. It comes in two sizes, full-size and mini. Mini Displayport is usually associated with laptops, but not always. Displayport (also known as Thunderbolt) is digital, and supports very high resolution displays, such as 4K and 5K. You can also get a splitter cable and connect more than one monitor to a single Displayport port.
DVI is the legacy standard for connecting flat-panel displays digitally to video cards. Many flat-panel LCD and LED monitors have one or more of these connectors. There’s nothing inherently wrong with DVI, but its resolution is limited to 1920×1200 or 2560×1600, depending on the version. Then again, if you’re looking to connect an old monitor to a new computer, that limitation isn’t going to affect you.
HDMI is a television standard, present on most TVs, but it works fine for computer video too. It can carry both audio and video in a single cable, which is its chief advantage. DVI has similar limits of 1920×1200 or 2560×1600 resolution, but, once again, when dealing with an older monitor, that’s not a problem.
VGA is a standard that’s been around since the 1980s, first popularized by the IBM PS/2 from way back in 1987. There are probably a couple of billion devices with this connector on it (at least), but it’s analog, so it’s the lowest common denominator. It will work, but if you have another option, you’ll be happier with it.
Cables vs. adapters
Cables that allow you to directly connect Displayport (aka Thunderbolt) to DVI or HDMI are relatively rare, allegedly out of concerns they could be used by pirates.
I don’t follow the logic, but that means you probably won’t find what you want outside of Ebay. But it’s worth looking; locally an adapter to go from Mini Displayport to DVI cost $30. By driving a few miles I found one for $10, which I paid, because I needed it right away. But a direct cable on Ebay cost me $3.52, shipped. I bought one, of course.
Adapters can be advantageous sometimes, though. A good example is a Displayport or Mini Displayport adapter with DVI, HDMI and VGA connectors on it. Get one of those and keep it in your laptop bag, and you’ll be able to connect to almost any TV, monitor, or projector you come across. These adapters can be expensive at retail, but on Ebay they cost around 10 bucks. Just be careful to make sure you get the right-sized Displayport connector. Desktops usually have regular-sized ones and laptops usually have the mini Displayport connector.
Adapters vs. splitters
When buying an adapter with multiple video ports on it, keep this in mind: Unless it’s specifically marketed as a splitter, assume you can only use one of the ports at a time. Splitters usually cost quite a bit more than simple adapters do.
The least expensive splitters have a Displayport or mini DP connector on one side and two VGA connectors on the other. With multiple monitor displays, you’ll be happier if your primary display is digital.
Digital vs. Analog
When possible, stick with Displayport, DVI, and HDMI. Digital connections mean no signal degradation–the signal is either there or not. Conversion often leads to degradation, at least in the analog world, but when you convert from one digital signal to another you don’t lose any quality.
Analog connections like VGA are susceptible to signal degradation, which lowers the quality of the picture. When you connect a computer to the same display via both analog and digital, the improvement with digital is noticeable. The photos are sharper, text is cleaner and easier to read, and the overall experience is much more pleasant. When you have both a digital and an analog display side by side, you don’t have to have 20/20 vision to notice the difference. You’ll resist using the analog display for long periods of time.
Caveats
The older the monitor, the lower the resolution is likely to be. Modern computers and software tend to take advantage of higher resolution displays, so a 15-inch LCD display with a resolution of 1024×768 can be pretty limiting, even though that monitor may have cost $600 when it was new. I remember how expensive they were. Today, a 20-inch 1920×1080 monitor can cost $100 on sale, and 1600×900 resolution is limited to sub-$100 budget monitors. I have some advice on what to look for in a new monitor if you need it.
That said, the older monitor can still be useful as a secondary display if you have enough room on your desk for it. I frequently pull up reference material on a second monitor while I work on the newer, nicer monitor. And if you can make the second monitor work by buying a $4 cable, I understand why you might prefer to do that rather than spending $100 on a new monitor that might be overkill for a second display.
Going the other direction
Believe it or not, you may run into trouble going the other direction too. Cable standards changed after the 1990s, so I ran into problems plugging a 21st-century monitor into a 20th-century 486, requiring a cable modification or swap.
David Farquhar is a computer security professional, entrepreneur, and author. He started his career as a part-time computer technician in 1994, worked his way up to system administrator by 1997, and has specialized in vulnerability management since 2013. He invests in real estate on the side and his hobbies include O gauge trains, baseball cards, and retro computers and video games. A University of Missouri graduate, he holds CISSP and Security+ certifications. He lives in St. Louis with his family.