As energy prices soar this question has come back to life. Sadly, there is not a cut and dry answer to this.
I have no reason to doubt the claims that you can save about $100 / year per PC if you turn it off at night. However, energy is far from the only consideration. There are a number of pros and cons, some with price tags that can be calculated, others are quite a bit more fuzzy.
The Pros for turning your PC of at night:
- Energy Savings -- green is in and few would argue against the positives of saving energy.
- Rebooting is good for the system. This is why most IT people start the problem solving process by asking you to reboot.
- More Secure -- even the best computer security strategy is a step below in effectiveness when compared to powering off the computer.
I'm sure there are other benefits to shutting down at night, but let's look at the cons:
- Lost time getting started and ending the day. If you've been around computers for a while, you know the "jokes" about enjoying your first cup of coffee while the computer boots. After a while the joke isn't so funny.
- Wear and tear on the computer. OK -- this one is up for debate. With MTB (mean time before failure) on many hard drives approaching 50-75 years, it would seem that we have a lot of cushion on this one. There are other things to consider though. First, the electronics are impacted with heating and cooling cycles. Though this may be minor, it's still a part of the equation. Also, it's pretty well established that the most stressful part of operating electronic equipment is the startup. Think about your experience with failing electronics, when does it most often occur? When is a lightbulb most likely to blow? Leaving your computer on should reduce stress on the system and extend its life by at least a few nano-seconds.
- Backups, Updates & Virus Scans. This is tough. Depending on how juicy your system is, these background processes can have quite drain on the performance of your PC. To avoid the associated sluggishness we often schedule these activities for off hours. Can't do that if the PC is turned off.
So what's best? Well, it really depends. How much does down time cost you? Though still relatively rare, you are more vulnerable to downtime if you regularly cycle your power. Are you tolerant of background processes and updates running during the work day? You can't afford to let those lapse.
To me the bottom line is this. It's not a simple energy calculation. Lost time. Computer repair / replacement expenses. Risk of data loss. Regardless of how likely, there are other factors to consider. You need to determine whether the savings is worth the risk. For me, $100 a year in my pocket would be great... until something goes wrong and I'm left wondering if I had spent the $100, or less than $.50 / day, would I have avoided the downtime and it's associated costs? For me, that's money well spent, at least on some of my computers. For you??? Hopefully you have a little more information on which to make your decision.
BTW, modern computers have a lot of energy savings processes built in. There is probably a good happy medium for you depending on what you are working with.
