Requirements for Upgrading from Apple OS X 10.4.11 to 10.5

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Apple's release of Mac OS X 10.5, also known as Leopard, added over 300 features to the system, including the ability to sync your address book with a Yahoo account and inline editing of events in iCal. Though Apple has since updated past 10.5, each new version has stricter system requirements. If you want to upgrade older Macintosh computers in your office that can't support OS X 10.6 or newer, you may still be able to move from the last version of 10.4, 10.4.11, to 10.5.

Basic System Requirements

In order to update to OS X 10.5, your computer must have at least 512MB of RAM and an Intel, PowerPC G5 or PowerPC G4 processor running at 867 MHz or faster. Most notably, this excludes the PowerPC G3 processor that 10.4 supports. 10.4 also works with as little as 256MB of RAM. If your Mac does not meet these new requirements, you will not be able to install OS X 10.5.

Installation Requirements

Unlike more recent versions of OS X that support online updating, 10.5 requires a working DVD drive to run the installation disc. As OS X 10.4 also installed via disc, this should not exclude any computers unless your DVD drive is not functioning. The 10.5 installation also requires 9GB of open space on the hard drive. If you don't have enough space, you'll need to delete files and programs from your drive in advance.

New Feature Requirements

The new Time Machine feature in OS X 10.5, which creates backups of your data, requires an external hard drive attached to your Mac. Use of the DVD Player's improved de-interlacing requires a 1.8-GHz PowerPC G5 or better processor. All other feature requirements from 10.4, such as Front Row requiring a built-in infrared receiver and an Apple Remote, continue to apply in 10.5.

Installation

Inserting the 10.5 install disc on a Mac running any version of OS X 10.4 will automatically run the update program. The program will display all system installations and mark those that support an update with a green arrow. On most computers, you will see only one item and the installer will automatically select it. If you have OS X installed on multiple volumes on your Mac, you will need to pick which one to update.

Warnings

If your Mac has a third-party video card, remove it before updating to 10.5. After the update, you can download new drivers for the card -- if the manufacturer supports its use in 10.5 -- and reattach it. If you have a third-party SCSI card and your Mac won't boot after the update, try plugging a device or terminator into one of the SCSI card's ports. If it still won't boot, remove the card.