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Samsung SyncMaster XL20 LED-backlight monitor

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The XL20 is Samsung’s first LED-backlight LCD monitor, released about a year ago and promoted for graphics artists and imaging professionals keen on high color accuracy. SPCR’s interest in it was mainly to check the power consumption, as this is one of the often-repeated benefits of LED-backlight LCD monitors. My conflicted reaction to the XL20: The more I used it, the more I wanted to keep it, despite the audible (admittedly low) noise of its fan.

Dec 6, 2007 by Mike Chin

Product
Samsung SyncMaster XL20
Manufacturer
Samsung
Supplier
Samsung Canada
Market Price
US$1600~2000

LED backlight LCD monitors are all the rage in low power computing this year. The Apple Macbooks, OLPC XO and the Asus Eee PC are but a few of the many new notebooks to feature LED backlight LCD monitors. The main objective is reduced power consumption, which is certainly a holy grail in mobile computing. The trend is much weaker among stand-alone desktop LCD monitors, which are still dominated by CCFL backlighting.

Interestingly, when LED backlight technology first showed up (around 2004), the promise of power savings was secondary to improved color accuracy. The reality is that the LED-backlight LCD monitors showing up in laptops do not actually provide much better color accuracy than conventional CCFL backlight LCDs. It’s energy efficiency that’s taken the front seat. Environmentally, LEDs are also superior, as they don’t contain mercury like CCFLs, although they are not completely without toxic content (trace amounts of Gallium and Arsenic).

In contrast, the Samsung XL20 desktop monitor’s primary reason for existence is high color accuracy. This is Samsung’s first LED-backlight LCD monitor, released about a year ago. It’s promoted as a tool for graphics artists and imaging professionals. SPCR’s interest in it was mainly to check the power consumption, as this is one of the often-repeated benefits of LED-backlight LCD monitors. My reaction to the XL20: The more I used it, the more I wanted to keep it, despite the audible noise of its fan.


It looks ordinary, but once it’s turned on, the exceptional color accuracy of the XL20 is obvious to anyone.

SAMSUNG XL20 SPECIFICATIONS
Panel Viewable area 20.1"
Pixel Pitch (mm) 0.255
Brightness (cd/m2) 250 cd/m2
Contrast Ratio Static 600:01:00
Viewing Angle 178°/178°
Response Time (ms) 8ms (GTG)
Frequency Horiz. Rate (Analog) 30-92
Vertical Rate 56-85
Max Resolution 1600×1200
Supported Colors 16.7 million from palette of 1 billion
Inputs Input Video Signal Analog RGB, DVI
Sync Type Separate H/V, Composite
Input Connectors DVI-I, DVI-D
Plug & Play DDC 2B
USB Powered Hub Option 1 up, 2 down
Mac Compatibility Yes
Power On 85W Max
DPMS Mode <2W
Type Built-in
Wall Mount VESA 100mm
TCO TCO ’99
Color Black
Accessories huey Calibrator, Hood
Dimensions With stand (WxHxD) 448×390.8x220mm
Packing (WxHxD) 565x491x261mm
Weight Net 7.6 kg
Gross 11.7 kg
Stand Type HAS (100mm)
Function Height Adjustable Pivot

BASICS

Our sample was one that has been making the rounds to reviewers. The XL20 is bulkier than most consumer LCD monitors. This is in keeping with its image, as most professional monitors are bulkier, but the main reason for its larger size is that manufacturers seem unable to make LED backlight monitors smaller right now. The issue is having enough room for cooling. More on this later; for now note the large area of slots on the back of the unit. They are vents.

Despite its relative bulk, the bezel around the screen is pleasingly narrow, if not quite as svelte as the latest cheaper consumer models. The overall look is quite business-like, reminiscent of classic IBM (Lenovo) ThinkPad notebooks.

The monitor is fully adjustable for height, with a nicely damped action. It tilts back and forth, swivels on its base, and also pivots 90 degrees for vertical orientation of the screen. These are very nice features, but you’d expect them on a monitor that sells for upwards of $2,000. The stand came attached, and it unlocked with the removal of a small key.


The base rotates smoothly, and fully adjustable for height and pivot angle.
It contains a powered USB2 hub, with two output connectors.


Dual DVI inputs, power switch and cord connector all accessed from the bottom.


The menu controls are on the lower right edge of the bezel.

A DVI and a DVI-to-VGA cable are included, along with manual, drivers CD, and power cable. An A-to-B USB cable is also included for the USB hub. A hood comprised of three black plastic pieces is meant to isolate the screen from the effect of ambient light. Among the papers is a warranty card that declares a three year parts and labor warranty for the XL20 in Canada. Warranty terms may not be the same in all countries, so please confirm with your vendor. Finally, there is a USB device to calibrate the monitor for color and for ambient lighting conditions. The huey by x-rite is used with "GretagMacbeth" software on the computer to which the monitor is connected.


"huey Colorimeter"
in its cradle.
It
has photo sensors, LEDs and little suction cups on the other side to stick it on the monitor screen.

SETUP AND USE

Room was made on my desktop for XL20. Plug in the power cord, connect the DVI cable to the second port on the ATI X1800GTO graphics card in my PC, and turn the power on. A few adjustments in Windows to make the XL20 the primary monitor in an extended desktop, and we’re off and running.

Viewing the Windows desktop on the XL20 at its native 1600×1200 resolution means that compared to the 1280×1024 resolution on my main (typical) 19" LCD monitor, everything looks a bit smaller. The sharpness and clarity is excellent, which helps with text. I fiddled with the adjustments a bit. Aside from the usual range of controls, there are several modes: Custom, sRGB, AdobeRBG, Emulation, and Calibration. The brightness and contrast controls are only available in Custom; all the other modes are presets.

The hood comes in three pieces. The side pieces have little hooks that fit into cleverly hidden slots in grooves on the sides. The top panel then slides into grooves at the top of each side panel. It looks odd, but it could be useful in bright ambient lighting to keep the stray light from affecting your perception of the onscreen images. Many professionals use them.


Hooded for bright ambient conditions.

The installation of the software for the huey monitor calibration was painless. Calibrating the monitor takes just a couple of minutes. I set the monitor in Calibration mode, which gave an overly warm cast. The program calls for the wand tool to first measure the ambient lighting while facing the user. Then, the device is attached to the screen via the rubber suction cups mentioned earlier. The software runs through a gamut of colors and shades for a couple of minutes, at the end of which the monitor is declared calibrated. You can view the before/after color balance.


The huey wand affixed to the screen during the calibration process.

Was the end result better? Yes, it was better than all the other preset color modes, and seemed a bit better than my manual adjustments in Custom mode.

FIRST IMPRESSIONS

Even with the first viewing of just the black background desktop I prefer, the XL20 looked dramatic. Colors on little icons just jumped, especially the reds. When I looked at the photos taken the day before on a Nikon D80, I knew this was no ordinary monitor. The colors were stunningly vivid, better than any of my unretouched photos had ever looked on any monitor before. Colors and images fairly jumped off the screen, and the details under magnification were amazing. Moving a bit off-center to view the screen at an angle made no change in perceived colors. Now I began to understand the significance of Samsung’s claim that the XL20 can produce a color gamut of 114% of the NTSC standard, while standard monitors can only reach 82%.

I became distracted quickly and spent much time going through my archive of personal photographs, which often get forgotten now that so few of them get printed up. I had selected the best photos from a wedding in August, then optimized those photos with Photoshop to look balanced on my main monitor, which I’d adjusted to give a reasonable color balance. There was also a folder of digital photos at the same wedding taken and processed by a professional photographer with a Nikon D200 digital SLR one step above my D80. Comparing the photos was revealing. My own retouched photos looked oversaturated, especially the reds, on the XL20; the professional photos were much better balanced, very natural looking. The differences were so big that I went back to the RAW files of the shots from the Nikon D80… and discovered that on the XL20, they looked closer to the pro’s work, and more natural than my "corrected" versions.

When I viewed all these photos on my own monitor, the pro pics and my RAW pics both looked a bit washed out, while my "corrected" pics looked better saturated, though not as natural or balanced as the pro pics on the XL20.

All this made me pause. An aside:

If I want my photos to be color correct, then I need accuracy all the way down the production line, from camera to printing. If the monitor is inaccurate, there’s no point making color corrections with it. On the other hand, if the photos are mostly seen online (on the web), then they are subject to the huge variances among the millions of monitors used out there. Still, the more serious photographers would probably be using monitors that have better than average color accuracy — or so one would hope. I’ve read that lots of image professionals still hang on to their CRT monitors because they generally offer better color accuracy. Professional quality LCD monitors like the Eizo ColorEdge or the NEC SpectraView series run into the thousands, so they’re probably out of reach for all but pros. This probably means that most people viewing most photos on most computer screens don’t have the right colors. Hmmmm….

Back to the XL20…

All kinds of high definition video were played at full screen, and they all came off very nicely. Let’s face it, I’ve never seen better on any computer monitor. In fact, that’s the biggest difficulty of writing this review: I have nothing to compare against the XL20, it’s that much better than any other monitor I’ve ever had a chance to use. This is not just my opinion. The half dozen or so people who saw the XL20 in operation all had to stop, look and ask about it. Its superior image and color quality is that arresting and obvious.

There’s no way to do justice to any image on the XL20 with a photo of the screen; the best I can do is just show you one of the wedding photos, at 550px width. If you saw the original 4368×2912 image full-screen on the XL20 you’d swear the three girls were standing right in front of you. 😉


One of the wedding photos.

My main monitor is a BenQ FP991 manufactured in Dec 2003. It is an average monitor from its era. I chose it after carefully viewing at least half a dozen monitors in a store, and based my choice on perceived sharpness (for text clarity) and natural color rendition. I prefer it with the brightness and contrast turned down, as it’s easier on my eyes. Going back to it after the XL20 was difficult; not for ordinary usage, but for viewing photographs.

For general use, I found the XL20 a little too vivid and wanted to reduce the brightness. But setting the huey x-rite calibration software to automatically compensate for room lighting actually helped quite a lot, whether the room was at the slightly dim level I prefer when writing or the bright level it’s on when all the white-CFL lights are turned on for taking photos of products. The red LEDs on the huey wand flicker ever few minutes when it scans the ambient lighting; it’s quick enough not to be distracting, and you can set the scan frequency from 10 seconds to four hours.

THE LITTLE FAN

I mentioned at the beginning of this review that the XL20 has an audible fan. It wasn’t immediately noticeable at first, but once I settled down in front of it with my head no more than two feet away, I became aware of a steady whoosh, like white noise. It wasn’t immediately attributable to the monitor, but I realized that where it was coming from after a minute or two. An examination of the back of the unit revealed its location.


The little fan, seen from the back, at the lower center, behind the post of the stand.

The fan’s diameter is about 40mm, and it seems to be thermally controlled, as it gets louder after the monitor has been on for a while, shifting slowly from a white noise type of shhhh to a more machine-like whirr. At 20-22°C ambient, this transition occurred slowly, taking at least half an hour. Sound Pressure Levels were measured with our trusty B&K 2203 sound level meter from two feet directly in front of the monitor. The noise is slightly louder from behind the monitor, by 1-2 dBA depending on how far you are.

Samsung XL20 Fan Noise (SPL)
@2ft
At turn on
after one hour
XL20
21 dBA
23 dBA
XL20 + PC
23 dBA
25 dBA

The SPL at two feet represents the approximate distance between the monitor and a typical seated user. The first line of SPL readings is with just the monitor alone. The second set is the more realistic combined level of the monitor and the PC. (The monitor would not be on without the PC also being on.) For SPL at the standard one meter, just subtract 1 dBA.

When the monitor first turned on, the level is low enough to be masked by the ambient noise or the noise from the computer, even one as quiet as mine under the desk. (It measures about 22-23 dBA@1m but it is nearly inaudible from the seated position.) But as the fan in the XL20 slowly speeds up, after an hour, the noise becomes loud enough to be a bit bothersome if you’re used to a very quiet computer and no noise from your monitor.

NOISE RECORDINGS IN MP3 FORMAT

Most of our audio recordings have been made at 1m distance, in keeping with the distance we use to measure SPL. Some recordings are also done at 30cm distance, mostly for those sounds that are difficult to hear from a meter away. In this case, the rules have been broken, for a good reason: No one sits a meter away from a 20" monitor; you have to be within about two feet to work with it. No one sits just a foot away either, except when you’re peering at a fine detail momentarily. So, the recordings were all made at 60cm or 2′ from the front of the monitor. When comparing against other 1m distance component noise recordings, just treat them as if they were all recorded at the same distance. More
details about how we make recordings can be found in our
article: Audio Recording Methods Revised.

Each of the XL20 recordings begins with a five second interval of just ambient room noise, with no machines making noise in the room, followed by 10 seconds of the component noise. For best results, set your volume control so
that the starting ambient noise is just barely audible. Be aware that very quiet
subjects may not be audible — if we couldn’t hear it from one meter,
chances are we couldn’t record it either!

Comparative: Reference 120mm fan: 5V-7V-9V-12V, 5s Ambient between
levels
: One Meter,
One Foot

Why is a fan needed at all? This seems especially curious, because LED backlight monitors are commonly touted as being more energy efficient than the Cold Cathode Fluorescent Lamps (CCFL) used in most LCDs. I did notice some heat when I ran my hand across the top vents in the back, and the screen itself. It was time to measure the power consumption, which would tell us how much heat is being generated in the monitor.

POWER MEASUREMENTS

The XL20 was plugged into a Seasonic
Power Angel
to obtain AC power measurements in various states. For comparison, the 4-year old 19" BenQ FP991 LCD monitor was also measured under the same conditions. Data from a Samsung 931BW 19" widescreen LCD monitor is also shown. The optimal desktop results are the most relevant.

AC Power: Samsung XL20 vs other LCD monitors
Setting
XL20
BenQ FP991
Samsung 931BW
Optimal, desktop
67W
34W
26W
Max brightness, white screen
72W
36W
31W
Min brightness, white screen
36W
30W
15W
The XL20 is the only monitor in the group to feature Active Power Factor Correction. Its PF was consistently 0.97 or higher, while the others were at 0.61~0.67. High PF is preferable (greener) for more efficient delivery of AC power.

The results were shocking. The XL20 consumed twice as much power as the FP991, and over 2.5 times the power of the Samsung 931BW LCD monitor reviewed a few months ago. No wonder it needs a fan!

The following questions were emailed to Samsung Canada, who supplied the XL20 sample:

Why does the XL20 have a fan? LED backlight monitors are supposed to be more energy efficient. Why does the XL20 take double the power of other CCFL-backlight LCD monitors?

The answers took some weeks to return from techs in Korea, apparently, in a kind of shorthand:

"Luminance efficiency of LED is yet less than CCFL’s as of today but it keeps getting better. The efficiency of White LED is a little less than or almost same as CCFL’s but the efficiency of three color LED (R,G,B) is much less than CCFL’s, which XL20 is implemented with since it gives out much wider color gamut than CCFL and reproduces even better colors. To prevent the increase of internal temperature due to the low efficiency of three color LED, the fan is inside. Due to the efficiency mentioned above, it is about 1.3 times more than normal 20” LCD monitor with 1600 x1200 resolution."

The answer is self-explanatory, and the mention of three color LEDs leads us to a consideration of the backlight technology inside the XL20.

CFL vs. LED BACKLIGHTING

A discussion of these technologies can become quite complex, because there are several variants of both. I am no expert on LCD backlight technology, and my knowledge is based only on what I’ve researched for this and a couple of other monitor reviews in the past. Here’s a summary of what I found:

Conventional flat-panel Liquid Crystal Display monitors use Cold Cathode Fluorescent Lamps for backlighting. The light of the CCFL spans the visible spectrum, and this mixture of frequencies is seen as white light. Each pixel has three filters, one red, one green, and one blue; adjusting the amount of light through those filters results in various mixtures of red, green, and blue light. Because of the way the human eye works, different mixtures of those primary colors allow a person to perceive all the different colors across the visible spectrum.

The CCFL is usually a thin tube that’s about as long as the width of the screen. A white diffusion panel behind the LCD redirects and scatters the light evenly to ensure a uniform display. On its way through filters, liquid crystal layers and electrode layers, some of this light is lost. The CCFL does not emit light perfectly evenly all across its surface, which explains the generally greater brightness behind the screen.

Instead of a CCFL, Luxeon and Triluminos technologies use an array of red, green, and blue LEDs; again, humans perceive the mix of these lights as white. But when, for instance, the green and blue are filtered out of a pixel, you get the pure, saturated red of a red LED (unlike with the "white" light source of the CCFL, which permits a range of red frequencies through the filter). These purer primary colors yield better-looking mixtures, as well.

Samsung’s product literature actually has very little real information about its LED backlight. NEC, the first company to offer an LED-backlight LCD monitor, provides more details about the technology in their 2180WG-LED-SV. Judging from the text and images shown in this review by Digital Video Editing, a strip of 48 LEDs is used in place of a CCFL, apparently. A flash animation about Samsung’s "MagicSpectrum", which covers both CCFL and LED backlight monitors, suggests a different layout in the Samsung XL20 where the LEDs are more or less evenly placed across the back of the light diffuser. However, it’s also not clear whether the animation is a truly accurate depiction, as its primary function is marketing.

What about the LED-backlit LCD monitors on the latest notebooks that supposedly increase battery life and power demand? They are different in that use only white LEDs are used, not three different color LEDs as in the XL20.

CONCLUSIONS

The Samsung SyncMaster XL20 is not just a great monitor, it is an amazing imaging tool. The current price of over $1500 may seem high when 24" LCD’s can be had for under $500, but the closest competition comes from monitors whose prices start at over twice as much: The NEC 2180WG-LED-SV, one of the few LED-backlight monitors, is selling for around $4,000. The XL20’s extremely high color gamut of 114% might actually not be surpassed by any monitor at any price. Aside from the color rendition and great viewing angles of the monitor, the huey color calibration tool provides useful calibration and automatic adjustment for ambient lighting conditions. LEDs generally last much longer than CFLs, so the XL20 should give a long useful life, especially with good power/screen management on the part of the user. It’s not a bad long-term buy for a computer product, especially in light of the incredibly short life cycle of most computer gear these days.



There are two downsides to the XL20: It consumes nearly 70W in normal use, and its fan is plainly audible in a quiet setting. The power consumption is about midway between typical CFL-backlight monitors and similarly sized CRT monitors (which often run >100W). As Samsung mentioned in their email, power efficiency of LED backlight monitors will improve, so perhaps that will come in the next generation (which is probably in the works even as I write). On the positive side, the very high power factor helps mitigate the higher power demand a bit.

The fan noise is probably not going to trouble any graphics or photo artist or professional who would benefit from the color accuracy of the XL20. Their benefits from the display performance would far outweigh the cost in noise. For someone less dedicated to color accuracy and more sensitive to noise, the noise after the monitor has been on for a while could be bothersome. A dedicated silent computing enthusiast could probably find a way to swap the fan for something quieter, but with a product this pricey, you may not want to risk the warranty. The other option is to use it solely as a secondary monitor for imaging work and turn it off when it’s not being used. A pair of headphones with the music of your choice could be a perfect solution. Whatever, the quality of the noise is mild enough that it’s not really annoying. In a typical office, you’d probably never hear it above the ambient.

Judged by the goals set for the XL20, you have to give Samsung credit. They’ve created a brilliant color-accurate monitor at a price that seems way lower than anything comparable. A bit of noise is a quibble in the face of the XL20’s virtues.

Pros

* Dramatically vivid and accurate color
* Useful calibration and ambient light compensation tool
* Great stand
* Price
Cons
* Fan makes a bit of noise
* Uses twice as much power as similar size CCFL-backlight LCD monitors
* Price

Our thanks to Samsung Canada for the review sample and for their kind support.

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For authoritative discussions of LCD display technologies, check out Oleg Artamonov’s excellent guides in X-bit Labs:

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Discuss this review in our Forums.

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