Someone correct me if I'm wrong but doesn't an iMac's built-in power supply have a transformer that protects it from electrical surges? Isn't that how the old power bricks (still shipping with portable Macs and iOS devices) worked?
I use an APC UPS for all my electronic equipment. Well worth the investment. They come in a variety of capacities, for just the iMac I would suggest something like this: http://www.newegg.com/Product/Product.aspx?Item=N82E16842101349
I have one similar that runs my Hi-Def TV and other equipment in the living room. Works like a champ.
Probably OK to back-up a laptop but be advised that whenever the power is interrupted, an annoying, loud audible alarm goes off every 30 seconds. Apparently can't be deactivated. So you thought you could sleep through an overnight power outage Not if you buy this.
I've got APC surge protectors on all my electronics.
I'm consider buying an APC UPS for my iMac.
Stay away from the bargain bin surge protectors. Reasonably good surge protectors cost very little.
An UPS can provide added layer of protection. If you're running a home office, I'd put in the extra bucks.
For home users, an UPS something to consider.
Personally I have never used any form of surge protection on my computers / expensive electrical equipment and in the last 15+ years have never suffered any ill effects. It's the same story at my work, 30+ Apple computers (Pro's and iMacs) and no surge protection and again no ill effects - however I'm guessing the servers are probably surge protected.
Saying that, I guess for peace of mind and a relatively cheap cost it can't hurt.
Also, what is the difference between a surge protector and a battery back-up? These features are often conflated into one device, right? Does my new iMac really need both, though?
The APC audible alarm exists for a reason. Though they have a mute button.
A basic surge protector is $6. In the event of a lightning strike, your $6 surge protector will fry. Your iMac won't.
Well, I might as well spend at least $100 and ensure that I'm getting one of quality. I noticed surge protectors for over $200 but I think a $100 protector should suffice, right?
There is a difference between a "surge protector" and an "uninterruptible power supply (UPS)". It's like comparing a bicycle and a motorcycle. Both get you places, but one is far more complicated and offers other features.
A surge protector is basically an inline fuse that fails at a specified level, to protect the electronics that connect to it. Fuses work very well. If all you care about is not having equipment fried by lightning striking your home, a $6 surge protector will do that.
A UPS has a surge protector, but also a sizable internal battery. The sizable battery is if in the event the power goes out, powered equipment stays powered. They cost much more because they are much more complicated than a simple fuse. This is not about just protecting against a direct lightning strike against your home, it's about protecting against data loss by not having the computer lose power unexpectedly.
I'm not sure if they all do this but we have them at work and they make this awful horror-movie beeping/screeching noise when the power goes out.
For how long? Can you mute it?