Q: I’ve asked many people whether I should leave my computer running or turn it off every night and everyone has a different opinion. What do you suggest? – Sandy
A: The reason that most folks have a different opinion is usually because everyone has a different reason for either leaving the computer on or turning it off.
Many folks choose to leave their computer running because they don’t want to go through the long boot-up process when it has been turned off.
Others are concerned about saving electricity and then there are those that are trying to squeeze extra life out of their computer because they have heard that turning it on and off creates “thermal cycling” conditions that reduce the life of the electronic components.
There really is no right or wrong answer to this question, because it’s based on what you are trying to achieve.
Let’s start with the “extending the life” theories. In the early days of the personal computer, “thermal cycling” which refers to the cyclical changes to the temperature of the components was relevant. The repeated expansion and contraction of the numerous solder connections and the associated components were known to cause small stress fractures that created system failures.
The theory was if you kept the components and the solder connections at a constant temperature, you eliminated the possibility of a “thermal cycling” related failure.
Other esoteric views pointed at the wear and tear to the hard drive from being turned on and off 730 times per year and that the majority of hard drive failures occurred during startup. So, if you never turned off your computer, you also avoided those potential points of failure.
Today’s computers use components that run cooler, have far fewer solder connections and have no real exposure from thermal cycling. Hard drive failure is still a concern today, but there is no data that we can point to that shows that leaving your computer running extends the life of the hard drive, simply the theory of reducing wear and tear.
So if you hear anyone tell you that leaving it running will extend the life of the computer, they believe in the “theory” that it will extend the life.
The issue of saving electricity is a more tangible issue and again depends upon the age of your computer and what power saving features you have activated.
If your desire is to save electricity, naturally turning off the computer whenever you are not using it can save you money, but that isn’t practical for most of us. The amount of time that the computer will be idle is usually the factor that determines whether you will shut it off or let it go to “sleep”.
Virtually every computer in use today has circuitry and software to reduce the power consumption whenever the unit has been idle for a pre-set timeframe.
The easiest way to see if your computers are going to sleep is if the screen goes blank and the power indicator on your monitor goes from green to amber.
In this state, your computer is using far less energy than a 40 watt light bulb (as little as 2.5 watts for the computer and 5 watts for the monitor). The difference between turning it off and leaving it running in a power saving mode is pretty minimal when it comes to what it costs in electricity.
Your monitor or LCD screen is one of the biggest consumers of electricity, so if that is a concern, get in the habit of turning off the screen whenever you plan to step away from your computer.
We all want to save electricity whenever possible, but we all hate to wait for our computers to startup from scratch, so you will have to balance those two issues to decide what you want to do.
If you plan on leaving your computer running most of the time, be sure to install a battery backup unit ($40 -$80) instead of a simple surge protector to better protect it round the clock.
If you are going to be away from your computer for an extended period of time, in addition to shutting it down, be sure to unplug it from the wall. This will guarantee that it can’t be damaged from any electrical anomalies while you are away!
[tags]reboot, thermal cycling[/tags]