Energy consumption.

[Ferret]

I always thought that turning off computers would save enrgy, but I friend of mine says that the switching on and off uses a lot more power, so you save power and energy by leaving your computer on. Does anyone have facts and figures to back these views up?

 

[ssampier]

In the short term, in my understanding, that is true (ie you turn off the computer, someone turn it on in 10 minutes, etc). But longterm, I don't believe that's the case.

There is some thought that keeping the computer on keeps the component running longer so it's not exposed to the hot/cold stress.

During the day I like to keep it on. At night, I turn it off (the fans would keep me awake anyway).

 

[Vraille Darkfang]

That depends on several factors.

If you have your computer set up for Sleep/Hibernation Mode it uses very little power when in that mode. Your monitor can be a very big draw. Turning it off can save power without turning off your computer. But, most monitors have a sleep mode as well.

Laptops (with their smaller fans) tend to use less energy than a Desktop.

It will also depend on how long you leave it turned off. On the Weekends my Laptop is on when I get up, then off only before I go to bed. During the week, however, I don't get to turn it on until I get home from work.

When a computer turns on, I suppose it uses more energy (as it loads the Config & background programs). Depending on your set-up, that can take awhile.

The biggest difference between Off & On (Sleep Mode) is going to be Fan Power. An Off PC has no Fan going. An on computer will have at least the CPU Fan blowing & several others to boot.

Overall, I'd say turning the Computer Off will save the most Electricity.

However, much like some of the worst wear & tear on your engine is when you first turn it on, the same might be true of Computers.

Getting all the Fans Running, Hard Disk Spinning; all of the Start-up might be more wear-and-tear than just letting it run 24-7.

 

[Meloncov]

The general advice I've heard is put it into hibernation if you'll be gone for more than an hour and turn it off overnight.

 

[Darth K'Trava]

I leave the comp on but turn off the monitor when I'm not here. I don't keep the laptop running.

There was a story on the news about a house fire that involved a powered up laptop left on the bed. Dunno if it was a Dell with a defective battery.... Goes to show, don't leave warm laptops on when you're not using them.

 

[trancejeremy]

I'm inclined to think it's better to turn them off. Even if a PC used the maximum power it can suck when you turn it on, it's only for a few seconds, and the maximum is only a few times what the idle is (Like say, 400 watts vs 100 watts or so).

Here's a link on this:

http://michaelbluejay.com/electricity/computers.html

"It's a myth that it takes more energy to start a computer than to keep it running. It doesn't. You will always save energy by turning your computer off when you're not using it. If that's inconvenient you can always use the sleep or standby mode."

He doesn't have any proof really, but he does call himself "Mr. Electricity", which is good enough for me...

Wear & tear could be an issue, but realistically, you get a new PC every few years anyway...

 

[Ferret]

Thanks, I think the last on in the faq section answer my question

I've heard that when you start up a computer it uses the same amount of electricity than it would if left on and casually used for a week. I've also heard that PC's consume ridiculous amounts of power even on energy saving mode. Is it better to shut down the computer or use energy saving mode? I've heard that having a higher refresh rate and resolution on a monitor coupled with a higher performance computer (megahertz, etc.) uses more power. Is there a significant difference between desktop to desktop? -- Y. Gonzalez, Miami FL, 2000

(1) It doesn't take any extra electricity to start up a computer. You can verify this by measuring the consumption, as described on this site.

I'll be telling my friend this.

 

[Catavarie]

Sounds like a job for Mythbusters

 

[IronWolf]

Mine stays on all the time for the most part. I have a file server in the basement that handles all my file storage, so it has to be on for the other PCs to get to their data. Of course the machine in the basement sits down there with no monitor and is only a Celeron 400. The main desktop upstairs also stays on all the time. One, for convenience and two, because it runs several virtual machines that I may need to access at various times of the day.

Probably not the smartest for energy consumption, but I am one of those that believes you get better reliability out of a machine that runs all the time versus powering it on and off all the time. As for getting rid of a PC every few years.... Hhhmmm, my Celeron 400 is still running as a primary piece of the network so I like for my hardware to last more than a few years. Though I think even this might be more superstition than something based on scientific evidence!

 

[trancejeremy]

Well, I'm currently posting from a PC from that same era as your Celeron (a Pentium 2 400), which I use because to surf the internet and download stuff because it's a lot quieter and uses less energy (200 watt power supply, compared to 500 for my main computer). And I turn that off/on at least twice a day, probably.