Is it safe to run pc without UPS?

By dmudgal
Jan 11, 2008
  1. i wanna know that is it safe to run a pc without ups.......i mean if electricity cuts happen during a power on pc then wud it effect any hardware or not?
  2. AlbertLionheart

    AlbertLionheart TechSpot Chancellor Posts: 2,026

    UPS do 2 things:
    1 - they stabilise the power supply by taking out peaks and troughs.
    2 - the provide enough power for you to close your apps and power off the PC if you have to.
    If you can be confident that your power supply is good and have, say, less than 4 power supply fails a year I would not bother. I would advise you to get a surge protector that covers the telephone cable as well as the power supply - this will protect you from surges caused by storms.
  3. kimsland

    kimsland Ex-TechSpotter Posts: 14,524

    If your the national data archive association, then no it's not safe.

    But as a personnal computer user, UPS is an expensive item to have running all the time, just in case power cuts out.

    Usually it's software that is affected not hardware
    But if it is Hardware, then it's usually just the $50 Power Supply (which is cheaper than UPS)

    It really depends on your data and software running without fault. Or are you OK with waiting for the power to come back online ?

    A lot of people insure their computer against this (hardware) issue, and receive a new computer if it blows up (not literally !)

    So there you go - Yes, No, Yes, No, No, (It's up to you)
  4. captaincranky

    captaincranky TechSpot Addict Posts: 11,456   +1,759

    I would think

    That if the power went out, you would only lose the files you had open at the time. Beyond that, at next boot, go to safe mode (F8) and select "Last known Good".
    I wouldn't be a bad idea to unplug the PC (and your other electronics) until the power is restored and stabilized. I'm just paranoid I suppose.

    Other than that, (as suggested by AlbertLionheart) a surge suppressor. Too much electricity is way, way, way more deadly than not any.
  5. jobeard

    jobeard TS Ambassador Posts: 9,148   +597

    The answer is "How important is your DATA?"

    If you're an email / IM adict, then likely you can just replace the HD, reinstall the OS and move on.

    If you have your business accounting files, 400-500 CDs of music, or 1000s of
    family pictures -- you need to rethink the issue.

    When my area started to experience brown-outs (ie loss of power), I went and
    got a UPS to protect my systems.
  6. Tedster

    Tedster Techspot old timer..... Posts: 6,000   +15

    Very foolish. Not only can you lose data, you can fry your equipment. Surge protectors alone are not sufficient protection. I had one blow during a lightening strike and I still lost my system. An UPS is a very wise investment.
  7. Didou

    Didou Bowtie extraordinair! Posts: 4,274

    Using your computer during a thunder storm is foolish in itself. ;)
  8. AlbertLionheart

    AlbertLionheart TechSpot Chancellor Posts: 2,026

    Because most of the power surges that do all the damage come down the phone line.....
  9. Didou

    Didou Bowtie extraordinair! Posts: 4,274

    That's a danger if your phone line is connected directly to the computer, most people nowadays use a router so in a worst case scenario it's the router that will be put out of commission.
  10. kimsland

    kimsland Ex-TechSpotter Posts: 14,524

    @Didou, actually I saw the sense in Tedster's post straight away.
    Better to advise to have a UPS if the customer asks. Otherwise he will blame you if you say , don't get one, and his computer blows up !

    I've therefore changed my mind, and say yes a UPS is an excellent idea.
  11. AlbertLionheart

    AlbertLionheart TechSpot Chancellor Posts: 2,026

    This is darkest UK where people still have antique ISP access on a dial-up using string and brown paper for a 56K modem. Hence the remark about blatz down phone lines - incidentally I have seen a PC 'killed' by a surge that went straight through the modem router. Smelt a bit too.
    PS: string and brown paper is an effective insulator.
  12. JJNelson13

    JJNelson13 TS Rookie

    Definitely a wise investment. It is better to pay a wee bit more now than a whole bunch later to reinstall a hard drive in addition to all the lost files.
  13. AlbertLionheart

    AlbertLionheart TechSpot Chancellor Posts: 2,026

    It is not just the contents of the hard drive you will have lost - more than likely you will have to replace the motherboard, chip, RAM, PSU - in fact just about everything! You can claim against your insurance!
  14. Tedster

    Tedster Techspot old timer..... Posts: 6,000   +15

    fast moving storms in the desert are often unpredictable!
  15. captaincranky

    captaincranky TechSpot Addict Posts: 11,456   +1,759

    A lightning strike is not the same thing as a power failure......

    If you walk over to your computer and pull the plug, you will loose the CHANGES to the file you're working. It won't wipe your HDD. Plug it back in, everything that was on the drive, will still be on the drive. So, if the power suddenly cuts off, isn't that the same thing?

    A lightning strike is a different issue entirely. If you were on a line that was struck locally by lightning, it might turn the UPS's 10 pounds of now massively over-volted and over-amped ni-cads into something resembling a bomb.
  16. AlbertLionheart

    AlbertLionheart TechSpot Chancellor Posts: 2,026

    Almost all UPS equipment is surge protected so it will also protect anything connected to it.
    One point of order on this - if you are going to get a UPS, make sure it has enough current reserve to give you the time to save your work - and this should include the current needed to run the monitor as otherwise you will not be able to see what you are doing!
  17. captaincranky

    captaincranky TechSpot Addict Posts: 11,456   +1,759


    Do you see where a ten dollar plastic surge supressor may not be equal to the task of stopping an electrical charge capable of jumping an air gap of a mile.

    My original post was based on a worst case scenario. An actual lightning strike contains millions if not billions of joules certainly more than a surge supressor is capable of diverting to ground. Now, if the lightning hits a lightning rod and the wiring in the house is only exposed to some high voltage leakage from the incident, then hopefully all would be well.
  18. SNGX1275

    SNGX1275 TS Forces Special Posts: 10,689   +395

    Eh, just string a bunch of them together.

    /Don't do this
  19. jobeard

    jobeard TS Ambassador Posts: 9,148   +597

    normal power off looks like

    voltage     |
                |                   .
                |                   .
                |                   .
                |                   .
                |                   .
    when there's a power fluctuation things go screwy
    voltage     |
                [COLOR="Red"]|...................      .
                |                   .   .   .
                |                     .      .
                |                              .
                |                                .
                |                                .[/COLOR]
    The UPS will 'hold' the voltage steady (both directions) and ensure stability.
    A Surge protector only protects the UPWARD swings.

    Without anything, the time between A-B is where things are dangerous.
    ANY write i/o can be uncontrolled and cause file corruption on the cyl/track
    where the i/o takes place.
  20. SNGX1275

    SNGX1275 TS Forces Special Posts: 10,689   +395

    For that to happen, they would need to be big, sustained swings in voltage. The PSU is going to have capacitors and such that can maintain a steady voltage as long as the AC Source isn't completely terrible. So while its impossible to argue exactly what you said, I think it should also be pointed out that you are probably dealing with greater than + or - 10% swings in the AC Voltage before any of the output is going to be significantly influenced on the DC Output end the PSU is providing.

    Millions of people run without UPSs and if it wasn't safe we'd see a lot more PSU failures than we do. Likely PSU manufacturers wouldn't even warranty their products unless it was connected to a UPS if they needed one.
  21. jobeard

    jobeard TS Ambassador Posts: 9,148   +597

    Yes it is entirely possible to run without a UPS. However, there are some areas where
    power outages are a common occurrence. Personally, I would(and did) protect my investment with a UPS.

    btw: I built shortwave radios when I was a teenager and understand there are
    capacitors. While they have the function of smoothing the output voltage,
    the fluctuations occur due to unstable input and continuous current demands.
    Secondly, the ripple in output occurs in very small delta time -- like the graph
    shows, it's a delay in getting to zero that's the problem.
  22. nismo91

    nismo91 TS Evangelist Posts: 899   +15

    imo for home pc or something like entertainment pc.,
    you wouldn't really need a UPS....

    unless for business purpose.,
    please keep in mind those are very important so don't forget to keep it :)

    i have set of AVR (automaic voltage regulator)., UPS., and surge protector for my home pc. but i don't think any of them safe my PC's life cause of blackout... (it's very rare now here fortunately...) but as other mentioned, it's always better to have some "security" so that u won't lose some data cause of ridiculous reason...
  23. Row1

    Row1 TS Guru Posts: 326   +13

    safe as yanking the power cord

    when my comp gets hung up by some website's virus, and won't turn off, I just yank the power cord.

    been doing it for years.

    hasn't hurt the computer yet.

    that seems the same as computing without ups: loss of power.

    yes, you lose whatever you are currently working on. but you don't harm components.

    in the old days, hard drives were not made to stop in a certain safe way if power were suddenly lost. so you might "crash" the reading head of your hard drive if you were unlucky and suddenly lost power when the "head" was active. however, for years, hard drives have been made to handle this situation.
  24. kimsland

    kimsland Ex-TechSpotter Posts: 14,524

    UPS have been designed mainly for sudden loss of power.
    But they are also designed to stop sudden increases of power, as in a lightening storm.

    Pulling the power cord can corrupt system files and data, which is the part the computer is intended for.
  25. nismo91

    nismo91 TS Evangelist Posts: 899   +15

    yes for some reason sometimes its alright for you to done that...
    but i just remember that few days ago my friend's laptop hdd screwed up just after he did a force shutdown onto it....

    all data is gone instantly... and i don;t wish that for my laptop and desktop of course,... that's why UPS are such made for...
    i just remember one saying: never mess with your comp when you're defragmenting...
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