Install OS X Mavericks on Mac Pro1.1

1,1 cannot run anything greater than 10.7

10.6 is the best OS for that model of computer.

Apple only supports up to 10.7 on your Mac.

I prefer Lion, and I needed Lion to purchase and use a later version of some apps, though now it is even harder to get Lion compatible versions (another story).

Lion drops Rosetta, which may actually be a good thing. PowerPC / Rosetta on Intel has never been that good.

Depends what you need but if Apple drops all support for Snow Leopard.... it is nice to have Lion handy. Heck, you can dual boot and use both.

"Best" is or can be personal and subjective. It was not for me.

The hatter wrote:

"Best" is or can be personal and subjective.

Actually, it was a statement of fact.

Unsubstantiated.

Proof?

Give me some. You have not. So it is just your opinion, your word, nothing more.

I said I need Lion to run some new apps, I do not need or want Rosetta and it has 2GB overhead.

I gave some. You didn't.

Is security better? TimeMachine? lack of Recovery? same Safari, Mail and others.

Sure people don't like Lion, don't like change, but I do see actual improvements in SSD performance, video and other areas.

Tricksy, but possible — and as noted above, totally unsupported by Apple. I use it on a Mac Pro 2,1 with an upgraded Radeon HD 5870.

Mavericks has some good features, and some bugginess. YMMV. I use it for icloud compatability with an iPhone and a macbook Air.

If I remember rightly, it's much more tricksy — perhaps impossible — if you don't have an upgraded video card such as to be found in the later, natively mavericks compatible Mac Pros.

The easiest way that I found is this one here:

http://oemden.com/?page_id=531

The site also tells you if you need to repatch after any upgrades are released, which is very handy.

Very easy to do but cannot really be discussed here.

One thing I will say though which isn’t specifically about unsupported upgrades, is that please make sure you have at least one good backup and do your research first. This is partly because even supported upgrades go wrong. Even if yours goes right but you don’t like it reverting is a hassle if programs like Aperture have ‘upgraded’ your photo library.