Slashdot Mirror
Power-Saving Web Pages: Real Or Myth?
An anonymous reader writes "Are dark webdesigns an energy saving alternative to a snow white Google? The theory is websites with black backgrounds save energy, based on the assumption that a monitor requires more power to display a white screen than black. Is this a blatant green washing ploy by Blackle.com, or an earnest energy saving tweak for a search tool we use every day? To find out, PCSTATS hooked up an Extech Power Analyzer to a 19" CRT and a 19" LCD and measured power draw — turns out there is a not insignificant difference ..."
"turns out there is a not insignificant difference "
Double negatives are not not bad.
If you wait a few seconds, your watts will turn into joules.
"Are not dark webdesigns an energy unsaving alternative to a snow white Google? The theory is that websites with black backgrounds don't save energy, based not on the assumption that a monitor requires more power to display a white screen than black. Is not this not a earnest endeavor by Blackle.com, or a not earnest not green not washing not not not not not ploy by not Blackle.com? To find out, PCSTATS didnt't not hook up an Extech Power Analyzer to a 19" CRT and a 19" LCD and measured power draw — turns out there is a significant difference ..."
Mine would have been shot down for being too readable though.
Support the EFF and Creative Commons. The war is coming, and they're supporting you...
This.
It is obvious that black is good for the earth and white is bad.
Why do you think we have climate change? Because of white, of course. No one has even heard of climate change before white messed everything up.
Not only is white bad, white is unhip. What do you want at your disco? White lights? No, black lights produce the right mood.
Let's fight the white and save the world!
The real power-saving web pages are simple and clean ones that that use the least CPU time to load, without bloated Web 2.0 javascript mashups of dozens of irrelevant sites and web bugs that keep track of you. TFA doesn't seem to mention that.
Unless the screen is OLED, the answer to "does dark sites save power?" is a flat out NO.
How you do figure, where's your data? Their data clearly shows that a CRT displaying all white uses 85W, and the same monitor displaying all black uses 63W, which sounds to me like it's using 25% less power to display the black screen. For an LCD the difference is only about 10%. The grayscale comparisons clearly show a relationship between darkness and power draw.
"Our two-party system is like a bowl of shit looking at itself in a mirror." - Lewis Black
The LCD they tested is also 8 years old.
I'm not saying newer LCD screens would perform differently (dynamic contrast, local dimming, etc. == marketing stats boosting and terrible) but basing a blanket statement like "B) Websites with darker colours tend to cause the monitor to consume less power." on a test with one LCD monitor is stretching it.
People still have CRTs?
How ridiculous.
Ability to display perfect black color;
Ability to display more than one resolution correctly (useful for games, old video card = new games at reduced resolution);
Ultrafast response time, no input lag;
Reliable and have long life (people saying things like "My LCD started acting weird, but it's 3 years old, time for a new one", while my 12 year old CRT works great), but can also be repaired if necessary (well, other than the failure of the tube obviously);
More affordable than a 24" LCD that can display 2304x1440 (if such a thing even exists);
Great image quality.
The only advantages of LCDs are size, weight and power consumption - all of these are not primary features of a monitor, at least for me (the same way that I don't buy a car based solely on the fuel consumption, or a computer based on its power consumption and size - I look for performance and cost first).
No, the big power draw is from CRT displays.
Both of them. They'll die someday and things will be nice and green again....
Back in my day the CRTs were green... or sometimes amber.
Set your background to black, and all your text so it only displays half the time.
I eat only the real part of complex carbohydrates.
The above post has incorrect assumptions.
Standard LCD screens do not alter the intensity of the backlight based on the information displayed on the screen, and the backlight and it's inverter is the majority of the power consumption. In addition, the drive circuit that aligns the liquid crystals can work opposite from how you expect in a TFT. Most TN screens, for example, are white or light gray when unpowered - refreshing the pixels to a black state takes more transistor drive than making the screen white. This is the technology you will find in most portable devices and computer monitors.
Some LED-backlit TVs use dynamic backlight, or even zone-dynamic backlight, where (mainly to create ridiculous contrast ratio specs) the backlight is reduced to the maximum temporal white level needed, or for multi-area addressable systems, the brightest backlight needed in an area.
The only portable devices where the brightness of the screen data is directly related to energy consumption would be those with OLED screens (such as the Samsung Galaxy SII line). The individual pixels are miniature LEDs, and when a pixel is black, they are turned off. On these AMOLED display phones, a black wallpaper can use far less power.
When I think of "power-saving webpages", I may be more concerned about one that runs my CPU at 100% for several seconds to display a page, Slashdot.