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Question: How many watts is a Mac Pro 5,1 power supply?

I have a Mac Pro 5,1 2012. Does anyone know how many watts the power supply is? I've heard mixed answers everywhere, from 900 watts to 1200 watts, to 90, which I think they were confusing with a MacBook Pro 85 watt charger, but still.

I would also be interested in replacing the power supply if it is under 700 watts, as I am running 3 hard drives and the stock ATI Radeon 5770 alongside a Nvidia GeFroce GTX 960. Does the Mac Pro 5,1 use a standard power supply and connectors?

Anything helps!


Mac Pro, Late 2012 running OS X 10.12 Sierra

Posted on Feb 10, 2017 6:53 PM

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Feb 12, 2017 7:30 AM in response to Geotrax In response to Geotrax

The rule of thumb is stated in the opening post on that page:

limit your graphics card choices to cards that draw under 225w (75w from PCIe slot, and 75w presumed limit of each [six-pin] aux plug) for stable operation

If you wish to run a card with an 8-pin aux connection, those are said to require 150 Watts each. Just splitting a 6-pin aux cord into 8 does not double its power capacity.

If you overdraw the well-designed Mac Power supply, it will shut off under overdraw conditions to avoid damage. This is seen as working fine for ordinary work, possibly for days on end. Then you start a big Render and the Mac suddenly powers off.

Feb 12, 2017 7:30 AM

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Feb 13, 2017 5:06 AM in response to Geotrax In response to Geotrax

As others have indicated even though the Mac Pro PSU has a total capacity of 980 watts not all of that is available for video cards. Again as others have indicated using a standard Mac Pro the maximum you can allocated to a single video card is 75w from the PCIe slot itself, plus 75w from each of the two 6pin PCIe power cables making a total of 225w. (3 x 75w.)

If you had one video card that needs two 6pin power cables and a second video card that needs even a single 6pin power cable then you cannot do this using the standard built-in power supply. Even potentially a single video card might exceed the official limits if it needs an 8pin connection plus a 6pin connection. The Mac Pro does not itself support 8pin connections which can give 150w each.

To drive a second video card that needs additional power you need to add a second power supply. In theory this could be an external power supply but there is also a way to fit a second power supply in the space that would normally hold a second optical drive. See this page and the two links listed on it - http://www.macvidcards.com/do-i-need-an-additional-power-supply.html

Note: An additional power supply could be chosen that does support 8pin connections as well as 6pin connections.

Feb 13, 2017 5:06 AM

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Question: How many watts is a Mac Pro 5,1 power supply?