On Saturday 27 April 2002 22:11, you wrote: > Better still, switch the monitor off when you're not using it :-)
Sure. At least get it to switch to standby mode when not required. The problem with switching the monitor off with its own power switch is that you may be asking for problems, as some CRT monitors appear not to be designed with this in mind. I've had a (Sony G200) monitor fail twice at 14-15 months from new/repair with a PSU failure. Fortunately it's a three year warranty, but I don't want it to fail _again_. > [... snip ...] > you might save a few watts, maybe another 10W if you can manage without any > disk spinning permanently. As it happens I have on my desk at the moment a "spare" 13GB 5400 rpm Maxtor HDD, which I guess is not untypical of hard disks installed in new systems in the last year. The power requirements are stated as 360mA @ 5V + 780mA @ 12V. These are steady state currents; the 12V startup current must be higher. Again you have to balance the "wear" caused by start-stop operation of a HDD against the power consumption. Typically current desktop HDDs are designed for 500,000 hours MTBF based on continuous operation but only 30,000 stop-start operations. Factor in the cost of lost service & restoring data when a drive fails and the extra power consumption caused by continuous operation starts to look very cheap. > The power consumption of the CPU is supposedly > around 30W under load - modest compared to recent Athlons or 0.18 micron > P4s. Yes. You pump up the speed, you ramp up the power requirements - cutting the fab size does help... the Northwood P4s (0.13 micron) use just over half the power of the corresponding 0.18 micron P4, despite having twice as much L2 cache built onto the processor die. > > > A 15" LCD monitor will use 150W-200W less power than a 17" CRT which has > > a similar visible screen size. There's a worthwhile saving in desk space > > as well. > > I did the calculations a few months ago and it's actually a saving of > around 100W (my 17" Iiyama claims to take 130W, 15" LCDs seem to take > around 30W). I used this to show that replacing CRTs with LCDs purely to > lower power bills wasn't yet economic. (And 1024x768 resolution isn't > enough for me anyway :-) My estimate of the power saving was based on the Sony 17" CRT monitor. It actually uses more current on standby than a fully-active 15" LCD monitor I also posess. The other factor here is that the CRT monitor has such a high "power on" current surge that it will overload a 1000VA UPS to a dangerous degree (it will actually trip out a 650vA UPS supplying no other load - though the continuous "in operation" power draw is a lot less than this). For practical purposes, a LCD monitor has no startup surge at all. The CRT "power on" current surge appears to be associated with degaussing the screen; many people claim (possibly with some justification) that they've had floppy disks rendered unusable by this action even at some distance from the CRT itself. OK, it's not as important these days, but LCD monitors are going to be more "floppy friendly" as well. CRT monitors are undoubtedly better for some specific types of work - you can get more accurate colour rendition as well as higher resolution - that's why I still have the Sony monitor (and miss it when it breaks). On the other hand LCD monitors are completely free of the geometrical imperfections (wavy lines etc) which afflict even the best CRT displays. I do like the LCD because I can have it in front of a keyboard on a standard office desk (pushed against a wall) and still have about 15" of space to play with. With a 17" CRT the keyboard has to be placed quite close to the edge of the desk; ergonomically dangerously close if, like me, you like a decent wrist support, and want your face two or three feet from the screen rather than rubbing your nose against it. LCD prices have crept up in the last couple of months but you can still get a decent 15" LCD for about the price of a high-quality 17" CRT (though I agree you can get a budget 17" monitor for less than half that amount - with luck, even one that you might be able to bear looking at). Even 17" (1280x1024) LCDs are starting to look reasonably affordable. Regards Brian Beesley _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
