My Mac Pro too old for Yosemite?

Question

I'm still on Snow Leopard on my Mac Pro.  The build year does not appear in my system profile, but according to the Model name, identifier and serial number, it looks like my Mac Pro was built some time in 2007.  I purchased and started using it in January of 2008.  According to the model compatibility given by Apple, my machine may be too old.  It states that machines built in 2008 or newer are compatible with Yosemite.
Does this really mean that my machine is not compatible with Yosemite?

Answer 1

The firmware for the Mac Pro 2,1 2007 model is EFI 32-bit, not 64-bit, even though the processors are.
EFI 1.x is not supported, only EFI 2.x and higher and no you can't put that on your system.
If you have another Mac that is you can by using 3rd party (unsupported) to get the installer package, you can't get Mountain Lion or above from Apple AppStore.
So it can but it uses a secondary boot loader to achieve that.
You also are limited by PCIe 1.x and Apple doesn't want to support older graphic cards that are not 2.0 or later.
Having a 64-bit kernel and all 64-bit drivers in the end is part of the goal, just as dropping PowerPC and Rosetta in Lion, just as dropping 68k code in favor of PowerPC was in OS 9.1.
The Mac Pro 2006-7 began in 2005, and even the 2008 is not "ideal" and does not meet the UEFI standard for a 64-bit firmware.
It still works, even better today, but Lion is the last official OS and may not get security and Safari support updates.
Two year old news from when Mountain lion came out, or that lots of people are running 10.10.x on that box.
2006/2007 Mac Pro (1,1/2,1) and OS X Yosemite (  1 2 3 4 5 6 ... Last Page)