What Watts?

Discussion in 'Mac Pro' started by UltraNEO*, Jan 10, 2009.

  1. UltraNEO* macrumors 601

    UltraNEO*

    Joined:
    Jun 16, 2007
    Location:
    近畿日本
    #1
    Question regarding UPS.

    On a MacPro 3.2Ghz configured with..
    20Gb Ram, 5TB HD's, RAID card and ATI 3870 with the optional 30" ACD.

    How does one workout what rating of an UPS is required?
    I know a 1500VA is suitable but how long is the running time? 10~15mins? :confused:

    Is there anyway to measure the amount of energy my system is consuming?
     
  2. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #2
    The best way is to use a Kill-a-Watt (or similar), as it measures the amount it uses. Better than estimating it any day. :p
     
  3. UltraNEO* thread starter macrumors 601

    UltraNEO*

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    #3
    Ah, thanks dude. That's really helpful!
    Saves me trying to use the ole grey matter. :D
     
  4. nanofrog macrumors G4

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    May 6, 2008
    #4
    There's that, and the power consumption listed on components isn't always accurate. :eek: CPU's are a good example. :p
     
  5. Eidorian macrumors Penryn

    Eidorian

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    Mar 23, 2005
    Location:
    Indianapolis
    #5
    Please elaborate.
     
  6. nanofrog macrumors G4

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    May 6, 2008
    #6
    They don't always use the full power rating. It all depends on the load.

    Intel also has a habit of going a little high as well historically. Just check out the Power Consumption sections of previous processor reviews.

    BTW, the greatest variance I tend to notice is from the board itself, and not just from the various cards plugged into some/all of the slots. Nvidia's N200 equiped boards are a good example. That chip alone will change the total power consumed compared to the board (same manufacturer) without it. ~50W IIRC.

    It all adds up, and something like a Kill A Watt is great for removing the guess work. Especially when you can find them for slightly under $25USD. :D
     
  7. wizzracer macrumors 6502

    wizzracer

    Joined:
    Sep 17, 2007
    Location:
    Dallas, Texas
    #7
    Take total amps used x voltage = Watts.

    600 watts / by 120 volts = 5 amps,

    Always check your real world voltage at the plug. As they tend to be highier around 125volts.
     
  8. rontheancient macrumors regular

    Joined:
    Nov 22, 2005
    Location:
    USA
    #8
    With the MP in my sig, 4 drives, and Handbrake running, I was getting about 320VA on the Kill-A-Watt meter. Your Mac Pro would certainly use more, but really depends on what you are doing at the time (idle hovers around 220-250VA). Definitely get a Kill-A-Watt.
     
  9. nightfly13 macrumors 6502a

    nightfly13

    Joined:
    Jul 17, 2008
    Location:
    Ranchi, India
    #9
    Using a Mac Pro in India where we have power cuts on a daily basis I've learned a lot about this. I had an 800VA UPS (for the quick change over from mains to inverter) that was fine for my tower only (had separate ones for monitors and accessories). It was fine EXCEPT for when I was gaming. It could not even handle the 1 second change over with my X1900XT (power hog). Pretty frustrating to have the computer crash and boot - so I bought a big 1.4KVA with 2 huge batteries (180AH each) for my whole office/theater and now I get 3-4h backup without issue. I'd say for Mac Pro under stress (tower only) that 1KVA is probably ok.

    One thing about VA and watts - no UPSs have a perfect power factor, so take the watts you think you need and add 25-30% and that's your VA requirement.
     
  10. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #10
    No, nothing is 100% efficient. :( No room temp superconductors exist yet. :p

    APC has a calculator that can be quite handy. Even so, the Kill A Watt is handy, as you can determine what your specific system draws, and use that to calculate from.

    Given the BX1500LCD (1500VA/865W) can be had for $200USD street, it isn't too expensive, and should handle most Mac Pro systems. If nothing else, the added time can't hurt. :D So I use this as a "Worse Case" cost wise for a consumer unit.

    I like their industrial/professional lines, and they are more efficient. The additional time is nice, but you pay for it. ;) Heavily. :eek:
    So they're out of most peoples budgets, including mine. :p
     
  11. Eidorian macrumors Penryn

    Eidorian

    Joined:
    Mar 23, 2005
    Location:
    Indianapolis
    #11
    Of course you're going to do your power testing under full load. ;) SpeedStep is going to kick in otherwise.

    I should have picked one up off of NewEgg for $13 back around New Years. :(
     
  12. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #12
    DISABLE it. :p
    Are you serious? $13 ?!? I've never seen it for that little. :eek:
    Argh...I missed the boat again. :p
     
  13. Eidorian macrumors Penryn

    Eidorian

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    Mar 23, 2005
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    Indianapolis
    #13
    And the benefit of this is?
     
  14. nanofrog macrumors G4

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    May 6, 2008
    #14
    Allows the system (CPU's mainly) to operate at or near full tilt. You get a worse case scenario if you plan that way. Helps with PSU selection, or how much load you can add without smoking it.

    I've seen it happen, and know what it can take out first hand. Turned cherry red, then smoke. :eek: :(

    So I'm a little paranoid now. :p
     
  15. UltraNEO* thread starter macrumors 601

    UltraNEO*

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    Jun 16, 2007
    Location:
    近畿日本
    #15

    Yeah! I figured that much. I ain't figure out how much power it's consuming but it's definitely enough to keep my studio warm and cosy throughout the winter months. Then again there are three systems in here. So, I guess I should play it safe. Take measurements of power consumption levels when the network is busy crunching data and rendering worlds.

    O'bhoy... sometimes, those tasks lasts for days! I just assume the USB models would send 'prepare for shutdown' signals to the system when the mains fails? cause I don't wanna lose anywork.
     
  16. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #16
    USB cable and the software are handy. You should be able to set it up to automatically Shut Down the system.

    Not much use without it, as you probably won't be sitting in front of the system 24/7. ;)
     

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