Battery Backup for New Mac Pro

Discussion in 'Mac Pro' started by -Noodles, Jan 10, 2008.

  1. -Noodles macrumors regular


    Oct 18, 2007
    I'm waiting for tues. before purchasing the new mac pro to see if they update the displays as well. Currently I'm looking at amazon for battery backups as I'll want to protect the investment. Below is the one I'm thinking of going with:

    Is there anything I'm failing to consider or insufficient in this model to anyone else's eyes? Any other recommendations?

  2. absolution macrumors member

    Aug 30, 2007
    What Mac Pro configuartion are you thinking about getting? You'll need to consider the amperage draw of the complete system before you can figure out what size UPS you need. For instance, different video cards can increase the total amps that the system would draw.

    I'll be connecting mine (2.8 octo, 8800 GT) to a 1500va Cyberpower UPS. I think my MP will probably pull around 3 amps which is well within the 15amp limit of my UPS.
  3. amik macrumors regular

    Dec 11, 2007
    The one you linked seems like it might not be sufficient. Looking at benchmarks for the previous quad core (, you could bump the limit of the battery backup depending what display and accessories you require to have battery backup. Not sure what the power consumption numbers are for the 8-core.

    FWIW, I just purchased this one for our new mac pro.
  4. -Noodles thread starter macrumors regular


    Oct 18, 2007
    I'm thinking of going with

    3.0 or 3.2 cpu configuration
    8800gt video card
    2 x 1GB ram
    2 x 1TB hard drives
    2 x optical drives

    1 x 30" display (waiting to see if they update these next week or drop the price)

    if you just do an amazon search for battery backup you'll see the couple other models with higher amp/voltage whatever.

    if you go to the tech specs for the mac pro it lists:
    Line voltage: 100-120V AC or 200-240V AC (wide-range power supply input voltage)

    the battery backup i originally listed says:
    Output Power Capacity: 550Va/330W

    i'm assuming the 550Va covers the either of the 100-120V or 200-240V - no? i'm not very literate when it comes to electrical specs so maybe i've got something wrong.
  5. -Noodles thread starter macrumors regular


    Oct 18, 2007
  6. amik macrumors regular

    Dec 11, 2007
    Va is not the same as V. V stands for voltage. Your wall sockets are 120V, a clothes dryer is typically 220 along with welders and other high draw devices.

    Va is volt-ampere and it is a weird unit because Volts X amps = watts, but Va is used to describe power to reactive loads. This is where some load is being returned to the source as the current flow changes, and therefore the peak amperage draw is higher than would be indicated by a consumption rating using watts. Read more here . So 550 Va means at 120v it can deliver 4.58 amps to a reactive load. Va matters when you are sizing a cable or other component to carry the current and the power factor is less than 1 for the device being powered.

    The 330w rating is for resistive loads, so it can deliver 2.75 amps into resistive loads at 120v (330/120).

    A computer has a power factor less than 1 so it is important to size UPS units based on the maximum instantaneous current flow in either direction. That's why you typically see that the .6 power factor used in their calculations, 330/0.6 = 550.

    Disclaimer: I am not an EE (I'm an Environmental Engineer) but work around a lot of industrial electrical equipment, so if I am incorrect as any of this applies to computers, please correct me. I do know that many computers use power factor corrected supplies, which is a factor in UPS sizing.
  7. -Noodles thread starter macrumors regular


    Oct 18, 2007
    thx for the explanation - very helpful
    do you have any suggestions more around the $100 price range then, that can do the job?
  8. amik macrumors regular

    Dec 11, 2007
    I did a little googling but didn't find any under $100 that I would feel confident in recommending for your needs. There may be a deal out there though.

    For your reference, Dell lists their 3007wfp 30" monitor as having a 147 watt normal power consumption.

    Here is a thread at I found while looking for 8-core Mac Pro power consumption. The penryns are supposed to be more energy efficient but I haven't seen numbers.
  9. -Noodles thread starter macrumors regular


    Oct 18, 2007
    looks like I'll just pony up for the one you suggested then (APC Back-UPS RS 1500 LCD 1500VA 8 Outlet BR1500LCD). Rather be safe than sorry at the end of it. This'll handle the monitor too then right?
  10. amik macrumors regular

    Dec 11, 2007
    Yes, make sure the Mac Pro and the monitor are on two of the 6 battery backup outlets. Other, non-essential items can be put on the 2 "surge protection only" outlets so you'll get the longest battery runtime if/when you need it.
  11. -Noodles thread starter macrumors regular


    Oct 18, 2007
    great thanks for the help - :)
  12. netnothing macrumors 68040


    Mar 13, 2007
    I have the Back-UPS XS 1300 LCD for my 2.66 Mac Pro with a 23" ACD and external HDD.

    The only other things plugged into the UPS are my cable modem and linksys router.

    Currently the LCD says I'll have:

    17 minute runtime with the LCD on
    23 minute runtime with the LCD off


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