Power-Saving Web Pages: Real Or Myth? 424
Posted
by
timothy
from the raise-your-hand-if-you-think-real dept.
from the raise-your-hand-if-you-think-real dept.
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 ..."
Re:Seriously? (Score:2, Interesting)
I bet "Anonymous Reader", our submitter, who probably shills for "blackle.com", "believes" it.
I can't decide if this story is an intentional slashvertisement or an astroturf.
"Blackle.com"? Really? It's only slightly clever to raise the possibility that they're trying to greenwash the issue of "website-specific power consumption", especially since TFS very conveniently refutes that. ("not insignficant?" Sheesh.)
Webpage almost crashed IE8 (Score:4, Interesting)
Maybe PCstats should apply their own power-saving strategies to themselves (less CPU-intensive flash crap).
Anyway it appears only the CRT has a significant savings with White google versus Black blackle.com. LCDs gain almost nothing.
What about the CPU? (Score:5, Interesting)
Firstly, I'm extremely skeptical of one of the conclusions - 'flash will make a CRT monitor use more power' - which I just don't believe - it will use an amount of power dependent on the average screen brightness - which may be an increase over black.
LCDs are different - the panel does actually take some energy to change state, and the lag compensation circuitry will use more in motion.
Secondly - a huge part has been missed out of this.
Power consumption of the computer.
Flash, or javascript, even in the background, can considerably increase power.
For example, I just closed all of the flash/animated things in the background on other tabs in firefox, and the CPU usage is now bouncing around 2%, with the computer using 17W.
If I start up a new tab with some flash, and gif animations, it goes up to 25W. (+8W)
Even switching away from the tab only takes it to 23W or so. (+5W)
It would be interesting to work out the total electricity wasted by common flash ads.
What about the rest of the computer ? (Score:4, Interesting)
It would have been interesting to include the whole computer in the power measurement. How much more electricity is drawn by a javascript infested site than one that is just static HTML and images ? How much more is drawn if there are 100 components to build the page instead of 20 (don't forget to include the consumption of your broadband modem, etc, ...) ? How much more electricity does flash use ? How much more through heavy use of AJAX ?
The biggest difference that they showed was that the use of a glass monitor was about double that of a LCD. With an LCD the CPU/... consumption would be a bigger fraction of the whole thing.
Re:Really? (Score:4, Interesting)
You should hate it. It's a shitty hack to make it look like your LCD has better contrast on paper.
I briefly owned a display like that. If I turned the dynamic contrast off, it looked washed out, and no amount of tweaking would get it looking even halfway decent. It was a shitty LCD but it was also 1/3rd the cost of my current photorealistic dazzlers.
It's the visual equivalent of the bass and treble boost knobs on cheap stereos.
Re:CRTs? (Score:5, Interesting)
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).
Re:Seriously? (Score:3, Interesting)
Readability: yes, please. (Score:4, Interesting)
Oh, so very, very much this.
Let me count the problems with light-text-on-dark-background:
1) If you have cataracts, corneal irritation, or smudged glasses, bright objects against a dark background are MUCH harder to resolve than dark images against a white background. With black-on-white, you just get reduced contrast; with white-on-black, you get distracting smears and rays all over the page.
2) In a dim room, your pupils dilate more if the scene before you is mostly dark, and dilated pupils generally produce poorer acuity. A bright background causes your pupils to contract, and just like stopping down a cheap camera lens, it improves the focus of the image hitting your retina.
3) In a bright room, a mostly-dark display will be more obscured by reflections and glare.
This is one reason I stopped hanging out at dpreview.com. Yeah, I know, photographers think their stuff looks better against a black background, but more than five or ten minutes on the site gives me a headache.