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I'm current using Corsair VS 550 (550 watt) power supply unit ,but i don't have any UPS. Is there any chance that my power supply unit and hard disk could be damaged for not using any UPS.can anyone help regarding this??

marked as duplicate by Xavierjazz, Excellll, Kevin Panko, Patches, Matthew Williams Sep 25 '14 at 11:28

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  • is this on one machine or a network with multiple servers? – ThunderToes Sep 23 '14 at 10:58
  • There is a very slight chance that a power failure at the wrong moment could cause your disk drive to become corrupted. But this is exceedingly rare on modern desktop systems. And modern systems have excellent built-in surge protection. So unless you live in an area with "flaky" power there is generally no need for either. – Daniel R Hicks Sep 23 '14 at 12:30
  • Related: Is surge protection actually needed? – gronostaj Sep 23 '14 at 13:25
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    It is good to use a UPS since it helps you to shut down properly from unexpected power cut off and also it protects from voltage variations. – Tomin Jacob Sep 23 '14 at 13:34

A UPS is an uninterrupted power supply meaning it's essentially a giant battery that is connected to your computer and, in the event of a loss of power, it will kick in and keep the computer running. While its primary purpose is not to prevent surge damage a decent UPS will include a surge protector (if I remember correctly power supplies do also). As @DanielRHicks said it is pretty rare that a loss of power can damage the machine especially compared to an unprotected surge.

In short (as Daniel said again) unless your power is really crazy you most likely won't need either. UPS adds another layer of protection against the very small chance of damage via surge and loss of power. Surge protector will only add protection against surges which your power supply should also have protection against. UPS's are relatively expensive so I don't think you'll need either. Exception: Servers or network vital machines. They should have UPS for power backups.

  • so,are you saying that a decent power supply contains protection against voltage variations? – Neo Sep 23 '14 at 15:42
  • Fluctuations not so much. Surge, yes. See a surge can destroy things. A loss of power can just cause it to blink out or corrupt information. A power supply doesn't retain power which you would want if you are looking at power fluctuations. – Griffin Sep 24 '14 at 12:47

A Smart UPS is a must, period. I've learned this the hard way just last week:

Had to move my table to another place in the room temporarily. A few evenings after that, current fluctuated badly. The result: computer shut down properly, monitor and external hard drive intact, router's power supply dead. Now guess which piece of equipment I did not bother to plug into the UPS because of the temporary nature of the move...

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    you tell us which one.. – Neo Sep 23 '14 at 16:06
  • the router, of course. – Dmitry Leskov Sep 24 '14 at 8:25

The risks might be limited for hardware damage, as other people have responded. However, you do risk data loss. You can lose your active work, and files can be corrupted. The hard disk can also be corrupted; that is generally fixable but you can lose files in the process. Weigh the one-time cost of a UPS against potential lost work and wasted time doing recovery.


A UPS is temporary and 'dirty' power during a blackout. Blackouts and brownouts do not damage any properly designed harmware. A UPS provides power so that data can be saved.

A UPS can also be some of the 'dirtiest' power seen by electronics. For example, this 120 volt UPS outputs 200 volt square waves with a spike of up to 270 volts. All electronics are so robust as to consider ideal even that 'dirty' power.

Read surge protection spec numbers for a UPS. Often hundreds of joules. Destructive surges can be hundreds of thousands of joules. A UPS is near zero protection. But just enough above zero so that many will speculate a UPS does useful protection.

Blackouts will not corrupt data on any disk drive - except if using an obsolete file system. How does a disk drive first learn of a power off? DC voltages start dropping. Normal shutdown and sudden power loss is same to every disk drive. But an obsolete file system (pre-1990 vintage) on a disk can cause files to be erased.

UPS is protection of data not yet saved to the disk. And if someone does not want to wait for a reboot. It does not protect data on the drive and does not protect hardware.

Voltage fluxuations: normal voltage for any computer is even when incandescent bulbs dim to 40% intensity. How often does your AC voltage fluxuate that much? Voltage that low is good voltage for any computer. If voltage drops lower, then a computer simply powers off. Low voltage does not cause electronics damage despite urban myths that say otherwise. Urban myths exist because claims are subjective; provided without the always required hard numbers.

  • Most modern UPS's (for example, Maxima) have wave-shaping circuits that guarantee a sine-wave output. – user312019 Sep 24 '14 at 14:31
  • Many UPSes provide provide power that is 'clean' and perfectly suitable for use with electronics. Further, defining "damage" as only whether hardware is harmed is too narrow in the world of computing. If hardware isn't injured, but my data is corrupted because of a power outage, I would consider that 'damage.' – Twisty Impersonator Sep 24 '14 at 14:32
  • Any electronics that is harmed by power loss (ie during a write process) is defective by design. That design standard even existed in disk drives when disk drives used motor oil to move its heads (ie long before PCs). – westom Sep 25 '14 at 17:57

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