Do I need to upgrade the firmware on a Mac Pro with mismatched processor config and serial number? I'm looking at buying a used Mac Pro. However, I want to know what I'm really buying as the serial number he provided does match the processor configuration in the about:



EveryMac says this is what the machine is according to its serial number:



The 2.4 GHz 6-Core configuration wasn't released until 2012 according to EveryMac:

http://www.everymac.com/systems/apple/mac_pro/specs/mac-pro-twelve-core-2.4-mid-2012-westmere-specs.html

So my question is, am I buying a 2009 Mac Pro, originally shipped with an "Eight Core" main board, but has been upgraded to a 2012 2x 6-Core main board?

If so, will I need to upgrade the firmware to match the new board?
The firmware had to have been updated before the newer processors were installed.

The differences between the 4,1 '09 &amp; the 5,1 '10 - '12 are minimal. What you're looking at is a hybrid, older machine [quad-core Nehalem originally] with upgraded firmware &amp; newer 6-core Westmere CPU.

In itself, there's nothing inherently wrong with that - I'm typing on one right now.
The fans are a little noisy - my older 3,1 you cannot even hear the fans until it's working hard - but it really has no issues, to all intents &amp; purposes it's now a 2012.

This is mine



The 5,1 upgrade does allow it to run Sierra too - I just don't like Sierra.