question regarding UPS (for power, not delivery)

UPSLynxUPSLynx :KAPPA:Redwood City, CA Icrontian
edited August 2008 in Hardware
May be a stupid question... should be easy enough but I just realized it's something I've never experienced or considered.

A friend of mine is building a new PC. She's putting a Quadro FX 3700 in it, and due to that and other hardware, she's picking a PSU that'll be around 800watts.

Her UPS is only 400 watts.

So what happens in a situation like that? I assume that the battery would constantly be drained, but is this essentially over-voltage, and could potentially be dangerous?

Comments

  • RyderRyder Kalamazoo, Mi Icrontian
    edited August 2008
    If the PSU pulls anything over 400W or even 400W out of the wall, then if the UPS goes to battery (and even before) it will just shutdown with overload.

    If the PSU is pulling only 300ish watts out of the wall at any given time.. she will be fine.

    It all depends on the power draw of the system (the elect that is actually coming out of the wall/UPS to the PC)
  • primesuspectprimesuspect Beepin n' Boopin Detroit, MI Icrontian
    edited August 2008
    You'll kill that UPS in no time. You need a better UPS for a modern system. a 300w ups is generally only good for office computers.
  • BlackHawkBlackHawk Bible music connoisseur There's no place like 127.0.0.1 Icrontian
    edited August 2008
    Need at least a 1kVA UPS.
  • LeonardoLeonardo Wake up and smell the glaciers Eagle River, Alaska Icrontian
    edited August 2008
    Need at least a 1kVA UPS.
    Nice to have but no, not necessary. A Quadro FX 3700 is based on the G92 GPU and should have about the same power consumption as an 8800GT. I would imagine the computer in question will have a max power draw of around 400 watts, considerably less during ordinary use. The rating of the PSU is irrelevant. What matters is how much power the computer is anticipated to draw on a routine basis from the wall, the UPS in this case being the wall. Most UPS units are not considered overloaded until the consistent power draw from them is 75% or greater of their rated capacity.

    If the purpose of the UPS is to keep the computer running for a relatively long period of time, then yes, a higher rating usually also means the battery is capable of discharge under high load for a longer period of time.

    I'm running two computers on a single UPS (systems 1 and 4 in signature). Both systems run overclocked Q6600s at 3.5GHz or higher. One system has a Quadro FX 3400 and the other an 8800GT. PSUs are 620 and 550W units. Both computers run Folding@Home -combination of GPU and CPU - full CPU core load 24/7. The UPS is an APC Smart-UPS (business class) 1500VA, 960kVA. Runtime on battery for both systems with a single LCD monitor is 8 minutes.

    Ideally, I'd like to have an equivalent UPS for each of my computers, but the cost would be prohibitive. The Smart-UPS 1500 that powers these two computers came from Craigslist for a song. I did though, have to replace the battery pack less than half a year after I purchased the UPS. But then, the battery was nearly four years old by that time.

    Keep in mind that UPSes are similar to PSUs in that the power rating doesn't tell the whole story. The electronics of the unit, build quality, and battery quality are also very important. I would stay away from generic or lesser known brands unless you are sure about their quality.
  • edcentricedcentric near Milwaukee, Wisconsin Icrontian
    edited August 2008
    Also consider what work the UPS will have to support. If you loose power your concern is closing applications and saving files. If you are in the middle of a rendering job you will most likely kill it and try to close safely.
    What will be powering the monitor?
    It sounds like she needs more. If you shop around you can find an 850-900 for about $100.
  • UPSLynxUPSLynx :KAPPA: Redwood City, CA Icrontian
    edited August 2008
    Guess I could have mentioned the PC will be used primarily for animation and rendering (maya, XSI). She hasn't settled on the rest of the hardware, but it's expected to be high end.

    Not sure about powering the monitor.

    So what I understand from what Leonardo was saying is that her current UPS, assuming it's of good quality, will do for now if need be. Still recommended she looks for a better one however. Until the PC is built, we don't really know the power draw. I'd assume rendertime power usage would peak... guess we'll have to wait and see.

    Is there any danger to potentially killing a UPS due to a system with too high a load? I'm really not familiar with the power semantics, not to mention the details of a UPS. I just know that I have one and run my PC through it :rolleyes:
  • BlackHawkBlackHawk Bible music connoisseur There's no place like 127.0.0.1 Icrontian
    edited August 2008
    FWIW, most UPS will alert you if it's overloaded.
  • LeonardoLeonardo Wake up and smell the glaciers Eagle River, Alaska Icrontian
    edited August 2008
    We'll need to know a close to final hardware list, then we can calculate the power draw. If the UPS is rated for 25% more power than the supported unit draws, then you're OK.
    If the PSU is pulling only 300ish watts out of the wall at any given time.. she will be fine.
    Would you please post a link to the UPS in question.
    Is there any danger to potentially killing a UPS due to a system with too high a load?
    Black Hawk is correct - most UPSes will have software or an indicator light to show if the unit is overloaded.

    Does her UPS have monitoring software. Again, a link to her model would be helpful.
  • UPSLynxUPSLynx :KAPPA: Redwood City, CA Icrontian
    edited August 2008
    OK, have some specifics for you guys.

    http://www.newegg.com/Product/Product.aspx?Item=N82E16842102044

    That's her current UPS. Not sure it's monitoring capabilities.

    She just needs something that'll give her time to save and turn off the PC in times of brownout and such.

    Her display is NEC multiSync FP2141 SB CRT. It probably uses a good chunk of electricity.

    She's pretty much got hardware finalized at this point:

    750W PSU
    ASUS Maximus II mobo
    Intel Q9550 mobo
    Quadro FX 3700
    8 gigs of ram (PC 1200)
    650gb SATA HDD
    2 optical drives and a TV tuner

    That rig is going to be a monster.
  • LeonardoLeonardo Wake up and smell the glaciers Eagle River, Alaska Icrontian
    edited August 2008
    That UPS should handle her computer and monitor, but will not allow much time on battery. It should be sufficient, but it's her call whether it will provide enough time on battery or not.

    According to the specification sheet, Newegg, that unit does have monitoring software. If your friend still has the CD, make sure it's installed and configured for automatic programs and OS shutdown. The auto software shutdown is preferred to just an abrupt computer shutdown when the battery depletes. We are not always so fortunate to be at our computers ready to take immediate action when there is a power outage.

    I don't know anything about the CyberPower brand quality.

    Once your friend completes her computer build, ensure to install the UPS software and run the UPS test.
  • BlackHawkBlackHawk Bible music connoisseur There's no place like 127.0.0.1 Icrontian
    edited August 2008
    If the disc isn't available, Windows can detect how much charge is left and shutdown, hibernate or standby when 10% is left.
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