Power consumption OUTRAGEOUS
  • I just got a 2009 Mac Pro with the following specs:
    Dual Intel Xeon 6-core 3.33GHZ. (Total 12 cores).
    32GB RAM.

    I have 24 Foscam cameras that are streaming 1080p resultion.
    I set SS to record motion, and continuous for all 24.

    I am in the USA, so we use 115V AC here.
    The Mac is pulling 24 to 25 AMPS!!!
    That is 2875 WATTS!!!

    This is INSANE! Is this normal?

    Prior to getting this Mac, I had a 2012 MacBook Pro with a quad core 2.7ghz. It was using max CPU power, but nothing remotely like this.

    My central air conditioner and refrigerator combined don't use this much power.

  • I should add that when I quit SS, the power consumption dropped to about 11 AMPS which is still very high. 1265 WATTS.
  • This does sound insane - something is not right with these numbers. If it were indeed consuming almost 3 kW, it would be glowing red hot after a short time!

    Apple has published typical power consumption figures for various Mac Pro models in this document: Mac Pro: Power consumption and thermal output information. A 12-core 2010 Mac Pro (the closest listed config to yours), has an idle consumption of 145 W and a maximum consumption of 285 W.
  • That amperage draw is above what a normal home circuit is capable of sourcing. Unless you have a specially wired breaker and larger than normal wiring, those amperage numbers simply are not doable. The breaker will trip before you get that high.

    A 20 amp circuit is already a special wired circuit in a US home, let alone drawing 24-25 amps. Something is not accurate. You would need a special circuit and highly unusual RV output socket and plug to achieve that at 115 volts.
  • Thanks. It is running on a 20 amp circuit.
    I tried two separate ammeters, and both are showing low to mid 20s for amps.
    I know often the circuit breakers will allow for a bit more than they are rated for but this is crazy.
    Originally I had it plugged into a 15 amp circuit, and it tripped it after about 8 hours. However, there was also a portable air conditioner on that same circuit which uses about 8 amps.

    Maybe I am testing it wrong? I don’t know. Not the first time I have used an ammeter.
  • At worst case, I really can't imagine anything in a functioning Mac Pro pull at much wattage. With the 8 hour run on a 15 amp circuit and finally tripping with an intermittent 8 amp co-load, you're MAX at 8-10 amps. That's still high, but not 20+ amps.

    I think something is awry with the metering or your house has already burned down while I was writing this. (Insert picture of badass kitty walking away as house burns in background)
  • Can you describe exactly where/how you are connecting the ammeter? I'm sure you're aware that if you're connecting it at the circuit breaker, this will measure the total current being used by all connected devices on that circuit. Are you sure the ammeter is designed for AC and not just DC?

    I presume your house has a master electricity meter somewhere, hopefully a digital one with a sub-kWh level of precision - you could use this as the basis of a rough test, as follows:

    - Turn the Mac off, note down the meter reading (x kWh)
    - Wait for 1 hour, then note down the meter reading (y kWh)
    - Turn the Mac on, wait for 1 hour, then note down the meter reading (z kWh)

    As far as possible, leave all other electrical devices in your house (lights, heating etc.) either on all the time, or off all the time, during this test (not randomly turning off/on).

    (y-x) gives you the baseline power consumption of your house in kW with the Mac off.
    (z-y) gives you the power consumption in kW of your house with the Mac on.

    So ((z-y) - (y-x)) gives you the approximate power consumption of the Mac in kW.
  • Ok, I found the problem.
    I was using this line splitter:

    And I was using this ammeter:

    Apparently the line splitter is causing an issue.
    When I tested it right at the circuit breaker where I don't need the line splitter, I was using about 3 amps with SS running.

    Not sure why the line splitter is causing such a false reading, but it was definitely the cause.
  • It does say that it's a "10x Line Splitter", so maybe the number it provides is ~10x the actual reading?
  • Yes. That's it. The line splitter includes a 10x coil.
    Readings using it are 10x what is actually flowing.
    Now it makes sense.

Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!