Apple Raid Card Battery cold at startup. Computer in a cold basement.

Discussion in 'Mac Pro' started by Bassin, Dec 2, 2011.

  1. Bassin macrumors newbie

    Dec 2, 2011
    My Mac Pro is placed in my basement, to avoid noise. But my basement is quite cold in the winter. So when I startup my mac, the Raid Utility warns me of a cold battery, and turns off caching. But after 1 min. the computer has warmed up, and everything is ok.

    Except for the risk of caching being disabled for 1 min. Is this ok? Do I risk anything by doing this every day?
  2. nanofrog macrumors G4

    May 6, 2008
    Do you have a UPS, and if so, what model, and is it working properly in the basement?
  3. Bassin thread starter macrumors newbie

    Dec 2, 2011
  4. interrobang macrumors 6502

    May 25, 2011
    FYI, Your Mac Pro is not intended to operate below 10C or 50F. You might want to warm the room a little before you boot.
  5. Inconsequential macrumors 68000

    Sep 12, 2007
    There is absolutely no technological reason why that is the case apart from if there is excessive humidity which might start condensing on the hardware.

    The bearings might not like starting from cold too much but once they are running and warmed up they will be fine.

    I ran mine at full load when my room was hovering around 0C (It was -10 outside and I was bored :p so I opened the windows!)
  6. nanofrog macrumors G4

    May 6, 2008
    When running a hardware RAID card, you really do need to be running a proper UPS (not all are the same). The reason for this, is that even with a battery backup unit attached to the card (aka BBU), if the data being saved is greater than the cache, you get a corrupted write anyway (= re-perform work). Another issue with a BBU is if it can't maintain the data long enough to get power restored (usually only an issue if the battery is weak or it's an extended power outage, such as a major disaster like a flood, hurricane, ...).

    But by having a UPS, it reduces this (can still happen if the write will take longer than the UPS batteries can run the system, and the BBU won't cover the balance <remaining capacity is still greater than the cache, or it's power dies before power is restored>).

    So the moral of the story is, get a good UPS...

    Some examples (US models BTW, but there are international versions available):
    BTW, the APC branded units can be had as refurbished models, and work just fine (make sure the electronics function properly and install a new set of batteries). The CyberPower unit is probably too new to find refurbished, but they're not expensive.

    Cost wise, the APC units are more expensive new, but refurbished will put them much closer to the CyberPower model <new> (there are some differences in the inverter types, but both will work with Active PFC based PSU's, which is what the MP uses and why you need to get the right model). Examples seemed easier than trying to explain every detail, but if you look closely at the Technical Details pages vs. cheaper units, you should see it (hint: inverter type; stepped inverters = damage A-PFC based PSU's. ;)

    • Now in terms of the temp, interrobang makes a good point; so what is the basement's temp when you're turning the MP ON?
    If it's colder than the specified operating conditions (also pay attention to humidity values), then he's right that you need to warm the room up. Or move it to a heated room and deal with the noise (MP isn't that loud; trust me, if you've listened to rack mount systems, you'll know what loud is :eek: :p).
  7. cutterman macrumors regular

    Apr 27, 2010
    FWIW, there is an increased incidence of mechanical hard drive failure at low temperatures, presumably due to lubricant failure in the spindle bearings. Otherwise the charging behavior of the battery seems normal and shouldnt hurt anything.

    +1 on the UPS
  8. interrobang macrumors 6502

    May 25, 2011
    Hot things expand. Cold things contract. If the environment is too cold, there will be a greater temperature differential between the "cold" and "hot" regions of the case; the components don't all warm up at the same rate. Subjecting components and solder traces to differential cooling is not a good idea for long term reliability.

    Apple says the minimum operating temperature is 50F. But what do they know, they're just a bunch of nerds.
  9. Bassin thread starter macrumors newbie

    Dec 2, 2011
    Thanx for all the replies. I will get myself a UPS.

    Probably will not be turning off the computer that much then. I will instead using the doze-function (can't sleep with Raid Card).

    Medium temperature will probably be around 5C in the winter, and maybe 12 in the summer. Will measure.

    Don't know about humidity. Will maybe find some way to measure that.

    Thanx for replies!

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