[fyeg_gen-l] Black screen doesn't really save energy

brunonicostrate brunonicostrate at yahoo.fr
Wed Dec 5 19:43:49 CET 2007

Hi Everyone,

Just to inform you that black screen doesn't decrease consumption of 

Google wanted to be clever by setting up its search engine in black 
(http://www.blackle.com), but it appears they are wrong:


We’ve boosted our testing to now include 27 monitors so we’re no pretty 
certain we know what to expect after our final series of tests.

Our tests on Blackle versus Google 
<http://techlogg.com/content/view/341/31/> has been reported on by major 
newspapers and sites around the world. Well, while a few people have 
managed to pull out a monitor or two to test how much power they consume 
running the two search sites, we think we’ll have to last word.

27 monitors.

Yep, we’ve tested 27 monitors, including some 23 LCD monitors, to find 
out once and for all how both of these search engines stack up on 
monitor power consumption.

We’ve taken a range of sizes and brands to try and get the most reliable 
test results possible.

There’s no argument that on CRT monitors, Blackle does reduce the power 
consumption but it’s not by the 15-watts claimed. We tested the four CRT 
monitors we could get our hands on and found that only one unit, an 
older 22-inch Compaq, showed the 15-watts or more power differential.

But with the LCD monitor market penetration worldwide now beyond 75%, 
it’s the LCD monitor power consumption that’s just as, if not more, 

The most interesting aspect we found was that of the LCD monitors we 
tested of size 22-inches or less, all showed an increase in power 
consumption using Blackle. Beyond the 22-inch mark however, five of the 
six models showed a fractional decrease in power consumption when using 
Blackle, except the ViewSonic VX2835wm, which showed a 2.2-watt increase.

For the five that dropped their power consumption, the average drop was 
3.16-watts, again, not the 15-watts being suggested.

But for the sake of fairness, here’s what we suggest – if you’re using a 
CRT monitor, you can save some power by using Blackle however it won’t 
be as much as its supporters will have you believe. We still think it’s 
around half.

If you’re using a 22-inch or smaller LCD screen, stick with Google if 
you want to keep power consumption to a minimum. However, if you have a 
24-inch or larger LCD monitor, on average, Blackle is the cheaper option 
but it’s not a guarantee – as we said, we found one 28-inch LCD monitor 
that bucked that trend.

However, the power consumption difference between Google and Blackle on 
all 23 LCD monitors was as small as you could get – an increase of 100mW 
(0.1Watts). So after all that testing, we’re in a better position to say 
that anyone else that Blackle makes next to no difference, on average, 
with LCD monitors.

If you’re really serious about saving energy, here’s just a couple of 
tips that will make far more difference: switch off your computer at the 
end of the day and don’t bother with a screensaver, because every 
screensaver costs power to run.

/*UPDATE August 10, 2007 - *If you're serious about wanting to save 
power with your computer, read this story. 
<http://techlogg.com/content/view/367/> We've outlined five simple ways 
based on our tests that we can all use to help save amounts of energy 
that far exceed what you can do with a search engine. /

/*Darren Yates is a B.Sc. (electronics) graduate of Macquarie 
University, Sydney, Australia. */

*Monitor* 	*Size
(inch)* 	*Resolution (pixels)* 	*Google
(watts)* 	*Blackle
(watts)* 	*Power difference (watts)*
*LCD models* 	
LG SW570LE 	15 	1024x768 	26.2 	26.5 	-0.3
AOC LM721 	17 	1280x1024 	33.1 	33.5 	-0.4
Acer AL1916W 	19 	1440x900 	28.3 	28.8 	-0.5
BenQ FP93G 	19 	1280x1024 	31.1 	31.9 	-0.8
LG L1917S 	19 	1440x900 	33.3 	33.4 	-0.1
LG L192WS 	19 	1440x900 	24.5 	25.1 	-0.6
LG L196W 	19 	1440x900 	38.6 	39.7 	-1.1
ViewSonic VX1932wm 	19 	1440x900 	35.5 	36 	-0.5
Asus VW202 	20 	1680x1050 	35.7 	37.2 	-1.5
BenQ FP202W 	20 	1680x1050 	43.6 	44.3 	-0.7
Acer AL2216W 	22 	1680x1050 	30.5 	32 	-1.5
Asus PG221 	22 	1680x1050 	54.9 	55.9 	-1
Asus VW222 	22 	1680x1050 	43.2 	43.4 	-0.2
BenQ FP222W 	22 	1680x1050 	40.7 	41.9 	-1.2
LG L226W 	22 	1680x1050 	39.9 	42 	-2.1
Samsung 226BW 	22 	1680x1050 	43.6 	44.8 	-1.2
ViewSonic VX2255wmh 	22 	1680x1050 	41.3 	42.4 	-1.1
BenQ FP241W 	24 	1920x1200 	87.4 	85.2 	2.2
Dell 2407WFP-HC 	24 	1920x1200 	82.7 	81.3 	1.4
NEC LCD2490WUXi 	24 	1920x1200 	73.7 	69.6 	4.1
NEC LCD2690WUXi 	26 	1920x1200 	89.3 	85.2 	4.1
ViewSonic VX2835wm 	28 	1920x1200 	106.8 	109 	-2.2
Samsung 305T 	30 	2560x1600 	111.5 	107.5 	4
* 	*
* 	*51.1* 	*51.2* 	*-0.1*
*CRT models* 	*
* 	*
* 	*
* 	*
* 	*
Acer AC915 	19 	1280x1024 	75.9 	64.6 	11.3
Compaq P1210 	22 	1280x960 	112.6 	96.2 	16.4
Digital PCXBV-HY 	15 	1024x768 	73.6 	65.1 	8.5
Mitsubishi DV1770 	17 	1024x768 	72.5 	65.4 	7.1
* 	*
* 	*83.7* 	*72.8* 	*10.8*

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