Mac Pro 1.1 Not Able to upgrade to Mountain Lion

I have a Mac Pro 1.1 running 10.6.8. I seem to have reached my last OS update as I'm told that this hardware will not accept Mountain Lion.

My question is: What's exactly is holding me back, the processors? If I upgrade the processors to X5355 2.66GHz Quad Cores will that clear the path for Mountain Lion, or am I simply stuck with a dinosaur that has reached the end of the road?

Thanks for any advice you can offer.

The main issue is the Mac Pro 1,1 does not have 64 bit EFI (only 32 bit).

There are some solutions to your problem. You need to search the internet to find them.

- Nick

The MacPro 1.1 will run Lion without the tricks Nick hinted at. It ran ok for me till the machine died. That's why I didn't look for options to run 10.8. 10.7 performance was ok for me but 10.6.8 was noticeably better.

My advice is to stick with the OS that is best for that very old machine and stay with 10.6.8 for now.

Something tells me that when the new Mac Pro comes out, prices on some of the older Mac Pros is going to drop like a rock. You might be able to upgrade from where you to a newER Mac Pro for a song.

The "Tricks" BTW don't work well with the older Mac Pros. Lion will work with no issue, but unless you bought it when it was available, it's not available to you on the App Store. Only way I can think of with 10.7 Lion is find someone with the Apple Flash Drive with Lion they were selling for a while, but buy that off them. Maybe someone on Ebay.

Otherwise, do what Chas suggested and stick with Snow Leopard.