Do Later LCDs Need Screen Savers?

bwdunn asks: "Do we need to run screen savers again to prevent the burn-in we saw on the very old CRTs? Dell's latest and greatest laptops, the Latitude D800 and Inspiron 8500 both suffer from horrible screen burn-in problems with burn-in visible after as little as 2 hours. Dell claims this is an industry wide problem. The high end displays from Apple also seem to have this problem. I have never seen this problem before 2002. Is this something new due to inferior LCD screen manufacturing compared to screens from just a few years ago?"

Comments

Turning Off Screen

[Sunlighter]

I bought a Dell Inspiron 5000E about three years ago (they are no longer made) with the expensive 1600x1200 LCD display.

Luckily, it doesnt have this problem. Ive used it every day for three years and not had any burn-in. None. Zero. Zip.

Another reason I'm glad my LCD doesn't have this problem is this: the energy saver just turns off the backlight. I can shine a bright flashlight on the display and see that the liquid crystals are actually still displaying the screen. Once I even moved the mouse pointer around while the backlight was off, and I could see it with the flashlight. (There is a button which turns off the backlight. It is positioned so that shutting the lid pushes it.)

Some screen savers also have a tendency to use the same areas of the screen, so watch out. "Blank Screen" is probably best because it really does set all the pixels to black, whether the backlight is on or not.

I wonder whether it is black or white which causes the pixels to "fade."

Re:Turning monitor off

[dubl-u]

Many household devices today use more power when their state is changed than they would if they were just left on constantly.

Go get yourself a meter like the WattsUp and gather some stats. In my experience, for computers there is an initial power surge that is maybe 2-3x normal draw, and lasts anywhere from 20 seconds to a couple of minutes. So worst case, if you will be turning your computer on again within 6 minutes, you probably should leave it on. Otherwise, turning it off will save power.

For screens, it's more complicated; CRTs draw more while warming up, but only for 15 seconds or so. But they draw less when showing a fully black screen, and different resolutions draw different amounts. Also, modern CRTs have assorted sleep modes. So whether or not to turn off a CRT depends on your usage patterns. For LCDs, I have no data.

I was also interested to note that high CPU usage produces measurable extra power usage. On a dual-processor P3/733 system, each processor pulls an extra 10 watts under load. So it turns out that things like SetiAtHome aren't free.

My mother, for instance, wastes more power than she saves by going around turning off all her fluorescent lights.

A common misconception, but not true. See this article for the details. They recommend leaving them on if you'll need them again within 15 minutes. But this isn't because of power usage; it's because turning them off and on too often reduces bulb life.

Aren't LCD monitors designed in the same way? They only use power when they are updated?

You'll note that in a dark room, you can see the LCD just fine. This means that it's producing light, which takes power. According to this week's Economist, "an LCD is only 10-15% efficient at converting energy from its power source into a readable image."

Re:Dell C810 – Sometimes you are only a warning.

[bellings]

The Dell Latitudes are not marketed to people who want high performance machines. They're marketed to people who want to be certain that if they order multiple machines with identical specifications they'll get multiple identical machines. Not only will you get several identical machines if you order them all at once (which is much more unusual than you may realize), but you'll also be able get identical machines if you order them again three months later (which is a much more common requirement than you may realize). And, you'll still have identical machines after the various warranty replacements you'll inevitably have over the next three years.

If you don't get any value from having multiple identical machines, then you don't want to buy Dell Latitudes. They don't offer anything of value to you. But don't act as if that means they don't offer anything of value to anyone.