Mac Musings

It's Official: Leopard Ships October 26

Daniel Knight - 2007.10.16

The Leopards are coming! The Leopards are coming!

This morning Apple began taking orders for Mac OS X 10.5 Leopard at the online Apple Store. As expected, the price is US$129 for a single user license and $199 for a five-user family pack.

Leopard can be preordered for delivery on October 26.

System Requirements

Most significantly, Apple has finally published official system requirements for Leopard: a DVD drive for installation, 512 MB of memory, and any Intel-based Mac, any G5 Mac, and any G4 Mac that's 867 MHz or faster. And Time Machine requires a second ahrd drive, either internal or external.

This leaves a lot of older Macs out in the cold, Macs that have been fully supported in Mac OS X 10.4 "Tiger": G3 iMacs, Pismo PowerBooks, the Blue & White Power Mac G3, all G3 iBooks, the first three generations of G4 Power Macs, some G4 iMacs, almost all titanium PowerBooks, and some G4 iBooks.

Maybe it's easier to list what is supported:

In addition, all versions of the Mac mini and all G5- and Intel-based Macs.

Can Leopard Run on Slower Macs?

That's the official story, and at this point we don't know the precise mechanism Apple will use to prevent users from installing Leopard on a Power Mac G4/533 MHz dual or an 800 MHz eMac.

However, we have heard that a hard drive with Leopard installed can be placed inside an unsupported G4 Mac - and it will work. No details yet on whether this applies to all G4 Macs or to any G3 Macs with G4 upgrades, but long story short you should be able to run Leopard on a dual 533 MHz Power Mac as long as you have a supported Mac you can use for the installation.

Unsupported Installers

The Mac community has been blessed by the efforts of Ryan Rempel, who developed XPostFacto (ex post facto is a Latin phrase meaning "after the fact") so that early versions of OS X could be installed on unsupported hardware. Version 3.1 supports OS X 10.2.x on PowerPC 603 and 604 Macs, while version 4 supports OS X 10.3 and 10.4 on G3 Macs - including most older Macs that can be upgraded with a G3.

Rempel made the XPostFacto project open source, so even though he's no longer answering email, hasn't been involved with the XPostFacto forums since the end of 2005, and may not be involved in developing an installer for Leopard, it's quite likely that someone will undertake the project.

Our guess is that all Mac designed around a G4 CPU will be able to run Leopard, the likely exception being the "Yikes!" Power Mac G4, which essentially grafts a G4 CPU onto a motherboard designed for the G3 processor. It seems very unlikely that the beige Power Mac G3 will be able to run Leopard even with a G4 upgrade, but there's a fair chance that a G4-upgraded Blue & White G3 could work.

We'll know a lot more in November, once users have received Leopard and tried their hand at getting it running on unsupported systems.

For those interested in further discussion of Leopard, we recommend Leopard List, our forum for those contemplating putting OS X 10.5 on their Macs.