MacPro 1,1 CPU Upgrade > Easier OS Upgrade


macrumors newbie
Original poster
Dec 23, 2013
So I know "google is my friend" but I haven't gotten a straight answer on this.

I've seen threads about cheap CPU upgrades for the 1,1. I've also read about the chameleon workaround for upgrading the OS to something more current.

What I haven't seen is an answer to this: Can a CPU upgrade address the OS upgrade limitation of the 1,1 MacPro?

In other words if I install a newer CPU in the 1,1 MacPro will that allow me to install something more recent than Lion?


macrumors 65816
Jun 13, 2003
Yeah, you can flash it, upgrade the CPU, and install Mavericks.

Question is, should you?

While I might be doing this myself, I'm going to do it AFTER I get my nMP, as if you run into problems flashing the 1,1, you just created an aluminum brick. I would not want to do this on a primary system.

If you are on a really tight budget, then this might be a viable option, just know the risks. (Depending on your budget and needs, an i7 hackintosh with a modern MB might be a better option).

I plan on using the 1,1 as a archive rig and perhaps media server.


macrumors regular
Jul 3, 2010
Los Angeles
installing new CPU's and upgrading the firmware to 1,2 will not allow you to run the latest OS on your Mac, to do that you will need to do the Boot.EFI hack on your Mac Pro and you could that without upgrading the CPU's.

I upgraded my Mac Pro 1,1 from 2.0Ghz quad to 3.0Ghz Quad and did the Boot.EFI to run Mavericks and using a PC based video card.
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