I’m about to send an e-mail to my entire company (10,000+ people) requesting that they each turn off their computers before going home at night in order to minimize energy costs. I don’t know why they chose me to do this, since it’s not in any way related to my job. But when the president of the company asks me to do something, I do it.
Anyway, before I send it out, I need to know whether this will really reduce our energy costs. I’m sure that there are knowledgable people in the company who already know the answer, and I don’t want to look like an idiot. I mean, it seems obvious that turning off 10,000 computers for at least 12 hours every night SHOULD reduce electricity consumption. But I just want to be sure. By the way, most of our computers go into “sleep” mode after a few minutes of non-use.
I wouldn’t go so far as to say “dramatically”, since a typical sleeping computer only draws a few watts. However, every little bit helps, and with 10,000 machines that can add up to quite a bit.
Yes, you’ll save energy by turning the computers off, but you’ll save more energy by turning the monitors off as well. For a long time I used to recommend that users leave the PCs on but turned the monitors off.
There are benefits to leaving computers on 24/7. How often are updates applied? Updating 10K machines is not a short task.
Any new monitor will drop current draw to ~0 if the signal disappears. It’s just common sense, and part of the whole Energy Star thing that was likely on the box when you got it.
I work for a large company with lots of computers that has debated this issue a few times. We have virus software and various other maintenance components installed that are set to run in the wee hours of the morning, so it is currently suggested they be left on all the time. Since most of our machines are new and have the standard energy saving features (monitors going to near-zero power use when signal drops, computer output signal drops if idle more than a certain period of time, disk drives power down if not in use, etc) it was deemed ok to leave them on.
I’m low on the totem pole right now, so having one of the older machines means most of the time that maintenance software just dies when it tries to run on my computer in power-saving modes, but sometimes it works.
I leave my home machine on all the time. To stave off complaints that it wastes electricity, I’ve likened the energy consumption of a computer in power saving modes to that of a nightlight, but I have to addmit that’s just a WAG
An idle computer only draws a few watts to run I beleive, the energy is wasted on the monitor wich draws as much current as a television (which it basically is) so even screensavers don’t really help, they just keep images from burning into the screen.
I left my computer on for a month (sans monitor) and off a month and didn’t notice any change in the electricity used on my bill
One thing you should take into consideration is the wear & tear of powering up the computer every morning, instead of leaving it on 24/7. When is a light bulb most likely to burn out? When you turn it on. Same with computers.
Bah. I don’t buy that. I’ve had the same computer at work for 5 years now and its been power on/off a few times every day virtually every day (save some weekends and holidays) for 5 years. I think you’ll end up replacing the damn thing before it breaks from “wear and tear”.
Yeah, but you have to understand that a computer doesn’t just “go out” like a light bulb. There’s no such thing as “wear and tear” in the context of a light bulb - the thing either works or it doesn’t. A computer, on the other hand, has thousands upon thousands of individual components, the failure of any which one probably won’t cause the computer as a whole to fail. For instance, if a single page of memory fails, it will probably only cause the whole machine to crash the one-in-a-million times it tries to access that memory address.
The point is, things like thermal stress aren’t just idle speculation - they’re reality, governed by the laws of physics. In the same way that you might flick a Coke tab back and forth a hundred times until it breaks off, every time you turn your computer on or off, thermal stress weakens the components a little bit at a time. One by one, those components will begin to fail and the computer will begin crashing more and more. Sometimes it’s just more noticable than others.
Actual power usage for my Dell 8200 computer, 21" Monitor, printer, cable modem and router using a watt hour meter.
In use .2507 kwh, for 8 hr day for 365 days = 732 kwh @ $0.10 per kwh = $73.
Leave on all the time, 2196 kwh = $220.
Saving in power = $147
Note: I only used the cost of $0.10 per kwh, most folks will be paying much more!
Unless you own the power company you are wasting your money to leave your computer on when not being used.
It doesn’t damage a computer to shut it down. I have a 7 year old IBM that has always been shut down when not used… it has never had a hardware problem.
Also shutting the computer down when not needed will help keep the inside of the computer cleaner… the fans always pull dust inside when running.
I shutdown my computer and monitor at my desk power panel… (double pole, double throw switch) that is almost as good as pulling the plug… for lighting protection.
Nothing is as good as pulling the plug for lightning protection. And that means all the plugs (phone, ethernet, cable) connected to the outside world. No mere switch is going to keep lightning from jumping the small gap inside them if that’s where it wants to go.
"One thing you should take into consideration is the wear & tear of powering up the computer every morning, "
Maybe on older computers, but not any more. Today’s computers can handle it just fine.
At our local college on e staff member turned her computer off at night but left the computer on in power saving mode. I asked her why & she said cause it takes too long for the monitor to warm up in the morning…but they still use power, look at the monitor manual for specs.
I have never unplugged… switching off at the double pole switch will protect 99% of the time. (first, you can’t unplug the central heating/air)I’m sure not going to unplug everything I have in my house every time we have a lighting storm. That is why I have insurance.
I know what lighting can do and what it normally doesn’t do. Several years ago, the pole behind my home took a direct hit… it fried everything in my home that had a 115 volt transformer, even including the doorbell. My freezer and refrig wasn’t hurt for they were not running. That was before I had a computer… had I had the computer it would have been protected with the open double pole switch.
No, it would have been toast too. Lightning can jump a 20-mile air gap from cloud to ground. What makes you think the 1/8" gap in a typical power switch is any protection?
