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Low Power Monitors from Samsung and Lenovo

Monitors are not our usual review subjects at SPCR. Ironically, the fact that they make very little noise (with a few exceptions) takes them off our radar; they’re usually quiet and we like that, but we don’t have too much more to say. That said, our interest in power efficiency (and some corresponding environmental concerns) has prompted us to take a closer look at a couple LCD monitors that bill themselves as “low power”.

October 7, 2009 by Devon Cooke

Product
ThinkVision L1940p Wide
19″ Widescreen LCD Monitor
Samsung P2070
20″ Widescreen LCD Monitor
Manufacturer
Samsung
Street Price
US$210~310
US$180~320

Monitors are not our usual review subjects at SPCR. Ironically, the fact that they make very little noise (with a few exceptions) takes them off our radar; they’re generally quiet and we like that, but we don’t have too much else to say. That said, our interest in power efficiency (and some corresponding environmental concerns) has prompted us to take a closer look at a couple LCD monitors that bill themselves as “low power”. (Editor’s Note: CFLs and other electronics inside modern monitors do often exhibit high pitched whining or buzzing sounds, as our Quiet / Noisy Monitor Survey has helped to document for the past year. However, the monitors reviewed here did not exhibit any audible noise.)

The first is from Lenovo, and some work has clearly been put into engineering a product that is kinder to the environment. The monitor complies with a number of environmental standards, including EPEAT Gold certification. The monitor first got our attention as part of Lenovo’s ThinkCenter M58p small form factor computer, where it impressed us enough to take a more detailed look at it here.

The second is a Samsung, and while the marketing emphasis is certainly less environmentally-centered than the Lenovo, the power rating does look pretty good.

LENOVO L1940p


Lenovo’s look is all business.

Power rating aside, the two monitors don’t have a whole lot in common. As you would expect of Lenovo’s business market, the L1940p is black, utilitarian, and businesslike. It offers practical features like a height-adjustable stand, a 90° pivot for use in a “portrait” format, and a means of hiding cables in the base. The buttons are large, easily accessible on the front bezel, and contoured so they can be found easily by touch. The appearance is a little stodgy, but perhaps that’s to be expected in a product line with a century’s worth of business machines behind it. What it lacks in sexiness, it makes up for in a feeling of solidity and quality. It adheres to the practical, utilitarian design principles that we often espouse at SPCR.


The stand is very flexible, allowing both height and orientation to be changed.


The five control buttons are large and accessible.

Despite its business simplicity, there are a few nice touches that make the
L1940p feel like a complete package rather than a budget buy. It features both
analogue (VGA) and digital (DVI-D) inputs, as well as a socket for a Kensington
security lock for public installation. The height-adjustable stand is worth
mentioning again. The head of the stand is highly flexible, allowing 45°
of left-right swivel in each direction, 30° of vertical tilt, and the aforementioned”pivot”
that allows the screen to be used at a 90° angle (though your graphics card
will need to support a similar function unless you are adept at reading text
vertically). If all that flexibility isn’t enough for you, it is also compatible
with a number of third-party mounts for wall-mounting and other exotic positions.


Both VGA and DVI are supported, and cables can be hidden in the stand.

Specifications: Lenovo L1940p
Panel Size
19″ Wide
Aspect Ratio
16:10
Resolution
1440×900
Screen Dimensions
408.2 mm (W) x 255.2mm (H)
Pixel Pitch
0.285 mm
Dot / Pixel Per Inch
89
Brightness
250 cd/m²
Contrast Ratio
1000:1 (typical)
Viewing Angle
(HxV @ CR 10:1)
160° / 160°
Response Time (Typical)
5 ms
Panel Type
twisted nematic, CCFL backlight
Power Consumption
(Typ. / Max / Sleep)
16W / 23W / <1W
Video Input Signals
Analog + DVI-D (HDCP)
Cables Supplies
Analog + DVI-D
Certifications
TCO’03, EPEAT Gold, GreenGuard, Energy Star 4.1, RoHS, Windows Vista, ISO DIS 13406-2
Tilt Angle (front/back)
0° / 30°
Swivel Angle (left/right)
±45°
Lift
4.33″ / 110mm
Pivot
90°
VESA Mount
Yes (100 mm)
Kensington Lock Slot
Yes
Dimensions (WxDxH)
440.2 x 241.5 x 356.1 mm
Weight
5.80 kg / 12.79 lbs

Technically, things seem pretty standard. It has a 19″ screen (a bit small by today’s standards) with a 16:10 aspect ratio and a native resolution of 1440×900. Contrast is rated 1000:1 (typical), and response time is 5 ms. The one spec that stands out is the one that caught our attention in the first place: Power consumption. This is rated at 16W (typical) / 23W (max), which is significantly better than the 30+ W that we expect of LCD monitors. We’ll see how accurate this is when we get to our test results.

Lenovo has clearly put some effort into getting the monitor recognized as an
environmentally friendly choice. Aside from the EPEAT Gold certification we
mentioned already (more info in this
article on Eco PC Review
), it also proudly displays compliance with TCO’03,
RoHS, and, interestingly, something called GreenGuard. GreenGuard is a little
outside of our area of expertise; the products they typically certify appear
to be building materials. Although they do have an electronics category, Lenovo
is the only company with certified products so far. The certification is for
air quality — specifically, with respect to potentially harmful chemicals
that may leach into the air from the products they certify. They have a
document that extensively outlines their test methodology
, but it is a little
beyond the expertise of this reviewer to comprehend.

COLOR REPRODUCTION

Color fidelity was tested by comparing a slate of ten original photographs with a high quality (if aging) imaging monitor, a Viewsonic G225f, calibrated with a Datacolor Spyder 2 monitor color calibration device, the previous generation of the Spyder 3. The L1940p was tested with various color profiles engaged, including a corrected profile calibrated in software using the Spyder 2. This corrected profile was used to see how good the monitor’s color could potentially be, rather than to evaluate its color performance out of the box.

Reference photos were taken of the Lenovo’s color reproduction, with the camera
white-balanced to a solid white screen on the calibrated reference monitor (nominally
6,500°K). This ensured that, as far as possible, color variances could be
attributed to the monitor, not the camera. Due to differences in brightness
across the various monitor profiles, exposure was not corrected for in the camera,
some artifacts related to brightness (notably the darker shadows in most shots)
can be seen that are not monitor related.


“Original” is the uncorrected original photo. “Stock
color” shows the color out-of-the-box (neutral setting). “sRGB”
was the most natural looking default setting, and “Corrected”
shows how the monitor looked after correction with the Spyder 2 calibration
device. Note the stark whiteness of the granite in the uncorrected versions
rather than the subtle earth tone in the original and corrected versions.

The L1940p includes four basic color profiles: Neutral, Reddish, Bluish, and sRGB. sRGB (the standard color space for monitors) looked the most natural, but natural is a relative term; all four default profiles looked very blue — even the “reddish” profile. sRGB also looks slightly greener than the other profiles. As often seems to be the case with monitors, all of the profiles seemed to exaggerate both contrast and color saturation. None of the default settings would be acceptable for color-sensitive work.

After calibration with the Spyder 2, the color looked much more natural, though
there were still a few minor deviations from the reference monitor, notably
exaggerated color saturation and a loss of detail in heavily saturated reds
that can probably be attributed to a smaller color gamut. Nonetheless, L1940p
is not intended as an imaging monitor, so these deviations are fairly minor.
In the vast majority of situations, the corrected color is probably good enough
for everyday use.


Here, the most noticeable effect in the uncorrected versions is the
disappearance of the golden sunshine on the mountain and the downpipe.
The uncorrected settings look colder thanks to the heavy blue emphasis.
The added green in the sRGB setting gives the sky a bit of a technicolor
look that is pretty but unnatural.

POWER CONSUMPTION

Power consumption is tied to the amount of light the monitor must produce, so power was measured several times with the monitor in two states: pure white and pure black. Power was measured at the wall with a Kill-a-Watt AC power meter.

Lenovo L1940p Power Consumption
Setting Screen Output Power Consumption
Default:
80 Brightness
50 Contrast
Black 14W
White 13W
Calibrated:
64 Brightness
63 Contrast
Black 11W
White 11W
Minimum:
0 Brightness
0 Contrast
Black 8W
White 8W
Maximum:
100 Brightness
100 Contrast
Black 17W
White 17W

With the exception of the “maximum” test, every single measurement we took bettered Lenovo’s average power consumption spec — and even that was only a watt over. The calibrated result of 11W was certainly the best we’ve ever seen for a stand-alone monitor. It’s quite likely it would be beaten by an integrated (and much smaller) laptop screen, but it’s pretty darn impressive for a stand-alone product.

Whether the screen was black or white did not appear to matter much for the L1940p. This indicates that most of the power is being consumed by the CCFL backlight, not the LCD technology itself. One thing that confused (and pleased) us a little was how much lower our measurements were than the peak power specified by Lenovo.

SAMSUNG P2070

Samsung’s P2070 is a much glitzier product, with a glossy black bezel, invisible buttons that light up to the touch, and a soft blue LED that illuminated the transparent plastic stem of the stand. It is a Mac to Lenovo’s PC; a work of art and sex appeal versus a utilitarian tool. The difference is immediately apparent in the marketing material on Samsung’s web site. The monitor is described in non-terribly-subtle sexual terms, with “ultra-slim dimensions” and “image quality that’s sure to catch your eye”. The most outrageous is probably this: “This SAMSUNG monitor gives you something beautiful to stare at, whether it’s on or off.”

Flirty as the marketing is, it disappoints when it comes to substance, which is frustratingly light on technical details and <ahem> hard data. Although it is apparently “eco-friendly” thanks to “a unique manufacturing process”, only by digging through several reviews of other monitors online was I able to discover that the low power consumption is attributable to a “dual lamp” design, and I was unable to find any supporting data about what that design entails.

Unfortunately, thanks to this dearth of actual, useful information or any environmental certification (including the somewhat basic TCO’03 certification), the ways in which the P2070 is actually environmentally friendly shall have to remain a mystery.


Oooh, shiny sexy black bezel. A soft cloth is included for cleaning —
A warning that it won’t stay pristine for long?


She looks good from behind as well…

The design principle of sexy over sanity is more than just skin deep. In comparison to the Lenovo, the Samsung feels very limited when it comes to actual use. The stand is short and not adjustable in any way except very slightly forward and back. There is only a single DVI-I input, with no adapter included for VGA inputs (luckily, the adapter included with many graphics cards should work).

Power is provided by an external 12V brick, which means more clutter under the desk. However, it does open up the possibility of replacing the default brick with a more efficient model if power consumption is critical (the small amount of watts saved will probably never offset the amount of power used to produce the new brick though…)


…but the input selection is kind of basic…

Perhaps the most irritating compromise between style and usability is the “Starlight
tough buttons” that are invisible until you prod around the bezel with
your finger to get five lighted icons that are touch-sensitive buttons. The
buttons only stay lighted for a limited amount of time, and do not provide any
tactile feedback. They are at their worst when trying to adjust brightness or
color when you need to be looking at the screen during the adjustment, not staring
at the bezel trying to find the right square centimeter to touch. Perhaps I’m
being unfair, but the already-clumsy five-button interface that all modern monitors
favor gets worse when you can’t tell where each button begins and
ends. But, yes, they are gorgeous. Just not very useful. (Editor’s Note: Ironically, this is the same problem I noted in my review of the Lenovo all-in-one A600 PC.)


… and her buttons are hard to find.

Specifications: Samsung P2070
Screen Size
20″ Wide
Resolution
1600×900
Brightness
250 CD/m²
Contrast Ratio
DC 50,000:1 (1000:1) (typ.)
Response Time
2 ms (GTG)
Viewing Angle (Horizontal / Vertical)
170° / 160° (CR > 10)
Colors Supported
16.7 M
Video Signal
analog RGB / DVI
Sync Signal
separate H / V, composite, SOG
Connector
DVI-I
Power Consumption (Typical / Standby)
26W / <1W
Dimensions (with stand)
500 x 382 x 190 mm
Weight
3.3 kg

The specs for the P2070 are quite similar to the Lenovo, with similar brightness,
contrast, viewing angle, and size ratings. One place where the Samsung does
seem superior is the aspect ratio, which at 16:9 properly accommodates DVD and
Bluray formats without cropping or boxing. The 1600×900 resolution is also slightly
higher — an additional bonus of the 16:9 aspect ratio.

One thing that is conspicuously absent from the spec sheet is any kind of certification.
While Lenovo pushed the envelope by getting the L1940p rated by GreenGuard,
Samsung doesn’t even bother with TCO’03. Though “TCO” is listed as
a possible spec, the rating for the P2070 is “No”.

Power consumption is rated significantly higher, at 26W typical (as opposed to 16W for the Lenovo). As before, these are specs only — we did our own tests as well, but the Lenovo will be tough to beat given how much it improved over its specifications.

COLOR REPRODUCTION

Color fidelity was tested by comparing a slate of ten original photographs
with a high quality (if aging) imaging monitor, a Viewsonic G225f, calibrated
with a Spyder 2 calibration device. The P2070 was tested with various color
profiles engaged, including a corrected profile calibrated in software using
the Spyder 2. This corrected profile was used to see how good the monitor’s
color could potentially be, rather than to evaluate its color performance
out of the box.

Reference photos were taken of the Lenovo’s color reproduction, with the camera
white-balanced to a solid white screen on the calibrated reference monitor (nominally
6,500°K). This ensured that, as far as possible, color variances could be
attributed to the monitor, not the camera. Due to differences in brightness
across the various monitor profiles, exposure was not corrected for in the camera,
some artifacts related to brightness (notably the darker shadows in most shots)
can be seen that are not monitor related.


“Original” is the uncorrected original photo. “Stock
color” shows the color out-of-the-box. “Hardware corrected”
shows a calibrated version using the red, green, and blue sliders in the
monitor itself, while, and “Software corrected” shows a calibration
done solely in software. Calibration was done with a Spyder 2 calibration
device. Note how unnatural the green cast of the default color profile
looks next to the original photo and the corrected versions.

Out of the box, the Samsung P2070 looked far more natural than the Lenovo.
The default color profile had a slight green cast, but nothing too serious.
However, the default brightness (set at 100) caused the blacks to glow quite
a bit; blacks looked much more natural with the brightness turned down.

A number of unhelpfully labeled color profiles are built into the monitor.
Each profile is labeled “Gamma Mode” followed by a number. No explanation
of what each mode corresponded to could be found, but they appeared to range
up and down the color temperature scale to be used “to taste”. There
was also a mode called “MagicColor”, which may or may not have adapted
to the ambient lighting in the room — the only explanation we could find
did little more but tout “dynamic” color, without explaining what
dynamic color might mean. In our lab, the effect of enabling it was to boost
the reds and saturation in a rather unnatural way. Because no good explanation
of any of the various color modes could be found, we did not feel justified
in testing any of them in detail.

On a more serious note, the monitor exhibited a serious color shift depending
on which angle it was viewed. Above 90°, the monitor took on a green cast,
while below 90° it looked magenta. The shift from green to magenta was sudden,
not gradual, and was particular annoying when the screen was angled at close
to 90°, since the color cast would change depending on the position of the
viewer’s head.


The lighting on the downpipe clearly shows the unnatural green color
cast of the default color profile. Corrected versions appeared much better,
but also much more saturated than the original.

Two separate calibrations were done with the P2070. The first was done “in
hardware” by tweaking the red, green and blue sliders in the menu of the
monitor itself. This calibration was less than satisfactory, since it tinted
the whites significantly even while correcting the midtones. We do not recommend
attempting any correction in hardware for this reason.

The second calibration was done with all the color sliders left at their default
value of 50, using only the custom gamma curve generated by the Spyder 2 sensor
to correct color fidelity. This method produced a much better result.

We also briefly played around with Samsung’s proprietary color correction utility
called “Natural Color Pro” — until it caused a BSOD on our machine.
We were unable to ever get this software working properly, even with the latest
version downloaded from Samsung’s web site. A different problem occurred with
the “Premium Magic Tune” utility which is intended to allow control
of the hardware menu via a Windows application. In this case, it simply refused
to recognize the monitor, popping up a message stating the monitor was “incompatible”
and then closing immediately. Like the Natural Color Pro application, downloading
the latest version from Samsung did not resolve the issue.

POWER CONSUMPTION

Power consumption is tied to the amount of light the monitor must produce,
so power was measured several times with the monitor in two states: pure white
and pure black. Power was measured at the wall with a Kill-a-Watt AC power meter.

Samsung P2070 Power
Consumption
Setting Screen Output Power Consumption
Default:
100 Brightness
75 Contrast
Black 24W
White 22W
Calibrated:
73 Brightness
75 Contrast
Black 19W
White 17W

As with the Lenovo, we were pleasantly surprised to find that the typical power
consumption the we measured for the P2070 was noticeably lower than the rated
consumption. This was particularly true when the brightness was turned down
to the correct level; power consumption averaged 18W. While it didn’t hit the
11W level reached by the Lenovo, the under-20W performance still puts the
P2070 in good company. Whether it’s Samsung’s “Dual lamp” technology
or something else, it still qualifies as a power miser in our books.

FINAL THOUGHTS

Perhaps it’s just the starkly different market segments they are targeted at,
but seems like the engineers at Lenovo and Samsung should have teamed up and
produced one monitor between them. Lenovo’s offering is eminently practical,
well thought-out, and usable — but very stodgy and a bit ugly. Samsung’s
P2070 is the opposite; here style appears to be the guiding principle, to hell
with usability (or comprehensible menu options). And both companies would probably
benefit from stealing an engineer from Apple to redo the awkward five-button
interface that has become standard on monitors for some reason.

Lenovo’s strength is in its focus on ergonomics and providing a complete package.
And, of course, its extremely power-frugal performance cannot be ignored —
if power efficiency is your main criteria in a monitor, this is your choice
hands down. However, color performance — especially uncalibrated —
was pretty poor. The extremely blue color cast may be acceptable for an office
environment where it’s all spreadsheets and word processing, but it’s not suitable
for any sort of color work, and it’s not the nicest monitor to view photos on
either.

Samsung’s advantage is style, a better out-of-the-box color calibration (if
you discount the odd color shift above and below 90°), and, if you watch
movies on your PC, its 16:9 aspect ratio. Its relatively efficient power performance
doesn’t hurt either, though it’s not good enough to stand out on the strength
of efficiency alone. Subjectively, it may have had slightly higher contrast
(and thus a punchier image), but it’s not clear whether this reflects more accurate
color performance.

The Samsung’s downsides are all related to the compromises made in the name of style
that sacrificed usability. Poorly labeled and unexplained menu options,
nonfunctional software package, and the maddening lack of any useful information
on its web site all speak volumes of a division run by marketing executives rather
than engineers. And, though it definitely exudes style, it has the cheap gaudiness
of a $10 disposable watch. If the P2070 were a woman as the marketing material
suggests, she’s is a tramp rather than a Milan supermodel.

Our thanks to Lenovo
and Samsung for
the monitor samples.

* * *

Articles of Related Interest
Lenovo ThinkCentre M58p Eco
USFF: Green Corporate SFF PC

Samsung
SyncMaster XL20 LED-backlight monitor

Samsung SyncMaster 931BW
How to stop the whining noise of your
LCD monitor

* * *

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