Hardware

10 things to look for in a flat-panel monitor

Flat-panel monitors offer numerous benefits, and quality (and prices) continue to improve. But you'll need to consider several factors when you begin to weigh the choices -- everything from resolution, latency, and power consumption to display controls and warranties. Here's a rundown of the key things to keep in mind.

Flat-panel monitors offer numerous benefits, and quality (and prices) continue to improve. But you'll need to consider several factors when you begin to weigh the choices -- everything from resolution, latency, and power consumption to display controls and warranties. Here's a rundown of the key things to keep in mind.


No longer a luxury, flat-panel monitors have largely replaced cathode ray tube (CRT) displays, and for good reason. Not only do flat-panel displays deliver sharper, crisper images, but they require less desk space and consume less energy.

In just a few short years, manufacturers have made improvements, too, in the quality and performance of flat-panel displays. Organizations that deployed early flat-panel models will find newer versions faster, brighter, generally more advanced, and even less expensive. Here's what you need to look for when making a purchase decision.

Note: This information is also available as a PDF download.

#1: Video input

The video inputs that a monitor supports are critical. Never assume a monitor matches your computer's default output.

Increasingly, desktop computers feature video cards with digital outputs, which produce better quality video than do older style VGA connections. In most cases, these digital video cards connect to flat-panel displays using DVI cables. Without a matching DVI port, a monitor can't easily be connected to such systems.

The same is true for computers using VGA (analog) outputs, such as those often found on common laptops and on countless desktops and servers. Be sure the systems' outputs and monitors' inputs match.

In some cases, users may need to connect multiple systems to the same monitor. Many flat-panel displays support only a single input, however, so if you'll be deploying a monitor in an environment where it will need to switch between two inputs, be sure that the model you select supports that feature.

In still other cases, users may need to connect higher-end video or gaming systems to the computer monitor, as well. HDMI inputs are becoming more popular for connecting such systems. Look for displays with HDMI inputs when such situations arise.

#2: Resolution

Monitor resolution is among the most important flat-panel display elements. Resolution is measured in pixels, first by width and then by height, using a number such as 1024x768.

If two monitors feature the same viewable size but one offers a greater resolution, the model with the larger resolution can display more information. For example, if one 17-inch monitor has higher resolution than a competing product, the model with the higher resolution will support displaying more pixel information. One common consequence of large resolutions, however, is individual items (such as icons and fonts) appear smaller. This is because more information is being squeezed into the same viewable space.

17-inch standard displays typically support a resolution of 1280x1024, while 20- and 22-inch widescreens can support 1680x1050 resolution.

#3: Size

Size is an easily overlooked benefit of flat-panel monitors. Flat-panel displays require far less desk space horizontally and vertically, and much less depth, than their CRT counterparts. As a result, you can typically squeeze a larger flat-panel screen into the same space that held a CRT monitor.

But there's also considerable difference in size between different flat-panel models offering the same viewing space. This is especially true when considering models that include speakers, which often add several inches to an LCD's trim.

If a flat-panel monitor is being squeezed into a tight space -- and many are when placed within cubicles beneath shelves, in custom point-of-sale locations, and within other sites -- pay special attention to a screen's total size. Just because a monitor is 17 inches wide doesn't mean it only needs 17 inches of clearance where it's being deployed. Models with the same viewable space can vary in total size by several inches.

#4: Latency

A monitor's latency, or response time, is another quantifiable measure of quality. Latency is the amount of time required for an LCD monitor's pixel to change from black to white and back to black. These response times are measured in milliseconds.

Displays with slow response times generate what some users describe as noticeably blurry images or video. That said, most modern flat-panel displays offer acceptable latency rates. While only hard-core gamers or video editors may require high-end response times, latency has become a standard measurement that helps indicate a product's true quality. High-quality displays typically have sub 5ms speeds. Lower quality monitors might rate 10ms or slower.

Note that a monitor's response time is different from its vertical synchronization rate, or the rate at which the entire screen is refreshed. Flat-panel monitors that use VGA inputs provide better performance when supporting higher (75hz or greater) refresh rates.

#5: Dot pitch

Dot pitch is another quantifiable measure of a flat-panel's quality. Manufacturers typically measure dot pitch in millimeters.

Often referred to as phosphor pitch, line pitch, or even pixel pitch, dot pitch is the diagonal distance between dots of the same color (red, blue, green) within the display. Lower dot pitch measurements are better and tend to indicate a display's ability to produce higher-quality, sharper images.

Low-quality displays usually have dot pitch measurements of approximately 0.29mm. High-quality monitors, however, may offer dot pitch measurements as high as 0.258mm.

#6: Contrast ratio

Flat-panel display quality can be measured by several elements, including contrast ratio. Contrast ratio measures a product's luminescent dynamic range, or the difference between the display's brightest (white) and darkest (black) pixels.

Higher contrast ratios typically indicate richer color reproduction and better image quality. Better quality flat-panel monitors sometimes offer contrast ratios as high as 1000:1, but more common corporate flat-panel models usually are in the 500:1 or 700:1 range.

#7: Viewing angle

Viewing angle is important, especially to teams that regularly collaborate. Whenever multiple employees gather around a single display to review spreadsheet data, build a presentation, or otherwise work together, the monitor must support the ability to view images and text for those seated on either side of the display.

Manufacturers measure horizontal viewing angle in degrees. When users must work together around a single monitor, look for models with at least 170-degree viewing angles. Such models enable clear views of the display 85 degrees from center (or basically when seated to the left and right of the display).

#8: Power consumption

Flat-panel displays consume far less energy than their old CRT counterparts. While average energy consumption is commonly estimated at 150 to 160 watts for traditional 17-inch CRT monitors, an equivalent 17-inch flat-panel display may consume as little as 35 watts -- just a fourth or so of that needed to power the CRT.

Power consumption varies widely, too, even among flat-panel models otherwise similar in size and price. A recent spot-check of two different 24-inch flat-panel displays from leading manufacturers revealed one model consumed 33 watts, while a competing product required 110 watts to power its operation.

You should always review a model's technical specifications before making a purchase. When you do, pay close attention to a unit's rated power consumption. Even a savings of 10 percent quickly becomes significant when deploying dozens of units.

#9: Display controls

Whichever flat-panel monitor you purchase, odds are that you (or your users) will occasionally need to adjust its settings. Whether you need to increase brightness, change contrast, or adjust color saturation and hue, the process proves much easier on displays featuring readily navigable controls. Many models feature only icons, which can prove confusing to some users, whereas others offer more intuitive onscreen menus pairing both icons and text.

Whenever possible, test drive a display before making a purchase. Or, if replacing numerous monitors, purchase and test a single unit before committing to a larger buy. Ensure that onscreen controls make sense to users and that they enable simple and quick changes to common settings, including brightness, contrast, color, input selection, setup menus, and even volume on speaker-equipped models.

#10: Warranty

Flat-panel prices continue to fall. Larger displays, boasting larger resolutions and faster performance, regularly appear at lower price points. And while manufacturers claim LCD backlight life spans of up to 60,000 hours, desktop technicians can tell you that monitors often fail within a couple years of deployment.

Protect your investment. When purchasing monitors, choose models with competitive warranties.

Since monitors aren't easily repaired, most organizations simply replace them when they fail (whether the failure is due to a problem with the LCD, a failure in the unit's power supply, or some other issue). Rather than incur replacement costs within a year or two of deployment, look for models that come with longer warranties. Three years is a good guideline for higher-end common desktop displays, while one-year is typical for entry-level units.

About

Erik Eckel owns and operates two technology companies. As a managing partner with Louisville Geek, he works daily as an IT consultant to assist small businesses in overcoming technology challenges and maximizing IT investments. He is also president o...

20 comments
melias
melias

I have been spoiled by Dell's Ultrasharp series (now Professional) and have to have my 4 USB ports available.

It's Just Me
It's Just Me

Don't forget adjustability (is that a word?). Not only tilting, but vertical adjustment. For those of us with bifocals, some screens stand too tall and we need to tilt our heads back just to bring the display into focus.

jsn2092
jsn2092

I notice that overscan was not mentioned. With the number of news and sports shows that use the bottom of screen scrolling information tickers, this would be an important consideration as well, since those with a high overscan would tend to truncate this area.

Marie55
Marie55

And what about 5000:1 or even I've seen 8000:1. What sort of activity needs that? As I am about buying a new monitor I wonder whether I need that high ratio.

manasseh
manasseh

There is a BIG difference between the 2 typical aspect ratios - 4:3 (like most CRT monitors of the past 20 years) and 16:9 (like most HDTV). A 17" LCD with a 4:3 ratio gives a slightly larger usable area than a 17" CRT. A 17" LCD with a 16:9 ratio provides a usable screen that is shorter and wider. Since many applications are designed for 4:3 ratio (think of a typical web site - limited width but scrolls to a semmingly endless length) and many users are accustomed to this ratio I would definitely consider this an important consideration. In my opinion, a 17" 16:9 is NOT an appropriate replacement for a 17" 4:3 - you really need a 19" 16:9 to get comparable height.

Jaqui
Jaqui

Frequency for the refresh rate. most of the flat screen monitors I look at won't give a refresh rate that doesn't hurt my eyes. I actually still use a CRT monitor since it's far easier to get one with a refresh rate I can use.

WTRTHS
WTRTHS

"If two monitors feature the same viewable size but one offers a greater resolution, the model with the larger resolution can display more information." That is certainly true, but I find many users prefer to use 1024*768 resolutions because it's easier to read, especially when not accustomed to higher resolutions. This is typically also the case for people who have trouble reading without glasses.

BALTHOR
BALTHOR

Somebody is doing hi rez computer animation so how are they doing it?YouTube quality is certainly inferior and SMPTE wouldn't pass it at all.

pdr5407
pdr5407

I think that LCD resolution is very important when chosing a monitor. For example, I have an acer monitor with 1680x1050 res and a DVI connection which is great for graphics and games. An LCD monitor should work for more than 2 years if kept in good condition. My old CRT still works perfectly after 5 years.

Erik Eckel
Erik Eckel

That's a good point. Most every flat-panel monitor is adjustable, now, but some more than others. Thanks for the reminder!

Erik Eckel
Erik Eckel

Aspect ratio goes in hand with resolution, which I mention within the #2 (Resolution) section. That said, most users are going to have a specific preference for a standard or widescreen display. I'd bet that 85% of my clients that requested new or replacement displays this year specifically wanted widescreen displays, incidentally.

Erik Eckel
Erik Eckel

I actually addressed refresh rates within point number four (the Latency section). Here's the applicable text, in case you missed it: Note that a monitor?s response time is different from its vertical synchronization rate, or the rate at which the entire screen is refreshed. Flat-panel monitors that use VGA inputs provide better performance when supporting higher (75hz or greater) refresh rates.

Neon Samurai
Neon Samurai

My understanding is that it's better to run LCD at native resolution so if it's a 1280x1024 screen you run the user desktop at 1280x1024 so your working with the same pixels. That would mean using large icons and fonts for your hard of seeing users though. Actually, it's not something I've found a perfect approach for as most user do simply reduce the resolution. Even back in my analyst days, the other analyst would run at less then the maximum of the monitor which only reduces the amount of screen workspace they have in Excel.

speculatrix
speculatrix

it's very easy for the manufacturer to make the numbers look good but produce an LCD monitor which is nasty to use. I wouldn't even mention dot pitch, it's irrelevant for LCDs, just give the screen size and pixel count. Dot pitch is a function of pixel count and size; with LCDs it's basically the same as the native resolution whereas with CRTs they're effectively different - the resolution is a function of bandwidth as well as the phospor dot pitch. contrast: be sure to look for the figure with dynamic contrast turned off, it's very easy for the display's maker to boost contrast to make the numbers look good for marketing but with the result of making the image bad panel type: look for PVA or S-IPS, avoid TN & STN and its variants. also check for 6,8 and 10 bit colour. colour gamut: look for wide colour gamut; not only is this a function of the number of bits, but also the quality of the backlight. inputs: ensure you have DVI or HDMI with HDCP as windows is now enforcing DRM on digital links and degrading picture quality during media playback. stand: it's useful to have height, front/back tilt and swivel adjustment. the better Dells (2408WFP) can also turn to give portrait format instead of landscape. accessories: you pay a lot for USB hubs, flash card readers, sound, webcams, etc, so whilst useful watch out for steep price premiums which are rarely worth it. best of all, check the anandtech lcd forums as they analyse the different panel types and go into the panel quality in detail.

Merlin the Wiz
Merlin the Wiz

Another item that should be considered is how the unit is powered. Does the AC cord plug directly into the unit or is there an external power pack that must be located close to the display. Sometimes the power pack must be placed on the desktop because the cable from the power pack to the unit is too short for anything else.

alec.wood
alec.wood

LCD monitors do not refresh in the same way a CRT does. There is no vertical scan. The refresh rate is immaterial unless you're watching fast moving video images such as games when you max it out purely as a way of maximising the data rate from computer to display. It's actually the absence of vertical scan and the increased contrast level which give some users headaches for a few days until they get used to it. Also, if they're used to a goldfish bowl CRT unit, they can experience some feeling of nausea while their brain unlearns the conversion of curved image to flat program it runs whenever you sit at your computer. Minimise headaches by turning down the contrast for the first few days of use, ensure you run only the native resolution - that's a must or you'll suffer eyestrain - and press that "Auto Adjust" button to fine tune the monitor's clock phase to match the PC

RipVan
RipVan

I have NEVER had good results using non-native resolutions. I always go native and change individual desktop settings or use various available "disability" settings across the entire desktop when necessary (mom-in-law).

pgit
pgit

I'm not positive but I think you can eventually damage an LCD by running it out of it's native resolution. I know I've seen 3 get killed over time, and all three were being run at an odd ball resolution not native to the system (btw 2 of them were on the same machine, same model of monitor, dies the same way) The only other failures of an LCD is it goes black. But those 3 above started having blank areas appear, obviously dead pixels. The areas grew to the point the screen was unusable in about a week once the problem started.

alec.wood
alec.wood

Sound advice. Non native resolution leads to anti-aliasing, and anti-aliased text leads to eyestrain headache. LCD should never be run at anything other than native resolution.

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