BleepingComputer.com: Power cuts and uninterruptible power supplies

Summertime means that our local power company conserves power (since electricity usage is increased markedly during these months) in the way of random power cuts. Now these power cuts are bad enough as it is, but the fact that we get no warning about it is what I really have a problem with. The fact that most people here are ignorant about the harm that a computer shutting down unexpectedly does doesn't help matters.

We had the first power cuts of the year, twice, last night (without any warning), and although my computer is running fine, it's just too much of a risk. The first thing I did this morning was back up everything. I'd still rather not have to replace my PC, as I just did so last year. So I'm thinking that a UPS would be a good idea to ensure safe shutdown and prolong my computer's lifespan.

My question is, is the potential for hardware failure or software corruption caused by a planned power cut high enough, that would warrant me purchasing an uninterrupted power supply? Or are power cuts not really that damaging to the computer software (as compared to, say, a power surge during a lightning storm, something that's not really an issue where I live)?

The info I've seen online is mixed. Some people suggesting that the chance of the system getting corrupted is extremely rare to be worried about it, with no chance of hardware failure for newer systems, and others saying that a power failure during a process such as the computer booting up have a good chance of of making the computer unusable.

Thanks.

This post has been edited by brc2000: 16 July 2011 - 04:27 AM

Quote

Having a computer shut off randomly isn't good for the computer and every time it's done there is a risk of corrupting the OS. On the hardware side theres not too much to worry about, but lets say you are doing a windows update and the computer shuts off.. when you try and turn it back on it may not come up if that update got corrupted.. Theres no guarantee that would happen but the chance is there.. If there are known issues with power outages you won't do anything but benefit from purchasing a ups.

This post has been edited by MarkGS: 16 July 2011 - 08:12 AM

Thanks. That's settled then, unless anyone has an opposing view.

Anyone know which brands are reliable?

brc2000, on 16 July 2011 - 04:07 AM, said:

If power cuts were destructive, then the part at risk would be defined with numbers. Only provided is speculation based upon an, "I saw this; therefore I know" reasoning.

For example, some know unexpected power off is harmful to disk drives. Nonsense. When do all disk drives (even in the 1960s) first learn about power off? When voltages start dropping. A hard drive first learns about power off when its 5 and 12 volts drop. All power offs are same - unexpected. To a hard drive, power off due to shutdown, yanking its power cord, tripping a circuit breaker, or a national blackout is same.

Someone once claimed a power cut caused computer damage. So we autopsied the power supply. A pullup resistor had failed maybe many months previously. That pullup resistor had only one function - to bootstrap the power supply during power on. Too many hours of operation resulted in a failed resistor. But most only know from observation. Saw no power on. Then just *knew* power off must be destructive. Power off did not cause any damage. A manufacturing defect maybe a month previously caused that failure.

A difference between those who know only from observation verses answers from those who actually do the work. Power off causes damage only when speculation replaces facts. When only observation (also called junk science) becomes proof.

Obsolete technology filesystems (ie FAT) could erase data when power was lost during a disk write. That problem was eliminated over a generation ago with the HTFS, NTFS, and other superior file systems. Sudden power off is a threat only to unsaved data ... except if someone is still using a technology obsoleted in the late 1980s such as Windows 3.1/95/ME.

I read that certain files need to be pout into place during the shut down process, and a sudden shut down prevents it. Many sources have also suggested that a shut down during a system file writing process can be destructive, and when my last hard drive was unable to boot, the first thing the computer repairs guy asked me was if there were any sudden shutdowns. I don't really know what to believe. Though I do know that forcing a reboot over and over again during a short space of time causes booting failure (from my own experience).

brc2000, on 17 July 2011 - 07:43 AM, said:

That problem existed with FAT. For example, if power was lost while updating a file, then the updated file was lost AND its previously saved version was also lost. Due to that defect (and so many still using Windows 98/ME instead of Windows NT), then many still believe this problem exists. Rarely, one can still find someone using an FAT filesystem.

HTFS obsoleted the problem. NTFS was created later. If power is lost before a file is updated, then the filesystem simply reverts back to the older file version. Are you still using FAT?

Nope.

So then this is all just widespread misinformation.

brc2000, on 17 July 2011 - 09:47 AM, said:

The computer repair industry is full of myths. For example, one needs no knowledge of how electricity works to pass an A+ Certified Tech exam. Key to cutting through so many myths is the 'always required' reason why. If reasons why are not provided, then suspect the worst.

An example. Many claim that rapid power cycling is destructive. A power controller (that most do not even know exists) will lockout to avert damage. That lockout function is reset only by disconnecting a power cord from the wall. Another function standard in computers but too often not known by computer techs. Many do not even know a power controller exists or what it does.

Too many know only from observation. Knowledge only from observation is classic junk science. Knowledge requires observation be combined with well proven and understood concepts. If he knew those concepts, then he also including those hard facts; the reasons why. Examples of what separates urban myths from hard facts.

Anyone else have an opinion on this? At this point it seems that a UPS isn't necessary, especially since I've read many reviews where people complained about malfunctions.

Well, myth or not, I see a "surge" in boot problems/blue screens and toasted power supplies etc after power outages. About two months ago I got 8 systems in due to problems related to a couple of blackouts we had. One of those annoying ones to. Power drops, comes back on, 30 seconds later it shuts off again and if you have your BIOS set to boot after power failure-double whammy.

I run a UPS on my system(s) mainly because I have Vonage and I like my phone/router/cable modem operational when the power drops. I have finally come back to APC for my UPS needs. Tried a couple of off brands, and not too happy (Belkin can kiss it).

Whether you use a UPS or not just depends opn how many blackouts/brownouts you have to deal with. Personally, I would invest in a UPS. I work on other people's stuff all the time and when it comes to my rigs, I am lazy. I just want them to work with minimal fuss. A UPS is just insurance for my laziness.

This post has been edited by dpunisher: 17 July 2011 - 11:30 PM