Is there a "hack" to make MacOS X 10.5 "Leopard" run on unsupported Power Mac G4 models?: EveryMac.com

Power Macintosh G4 Q&A - Published April 21, 2009

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Is there a "hack" to make MacOS X 10.5 "Leopard" run on unsupported Power Mac G4 models?

Apple reports that MacOS X 10.5 "Leopard" requires a Mac with an 867 MHz PowerPC G4 (or faster) processor, 512 MB of RAM, 9 GB of available hard drive space, and a DVD drive.

Consequently, Apple officially supports MacOS X 10.5 "Leopard" on the following Power Mac G4 models:

For the Maximum Supported version of MacOS X on all G3 and later Macs, please refer to the "By Capability" listings.

GenThree (now offline) created an application called LeopardAssist that provides a GUI to essentially "trick" the MacOS X 10.5 "Leopard" installer DVD to think that any AGP-based Power Mac G4 model has an 867 MHz processor prior to installation and then switch it back to the actual speed afterwards.

Please note that this application is no longer officially supported by the developer, but readers have noted that it makes the process quick and easy.

The superb OSNews reported that using LeopardAssist, it took merely "a few clicks" to install Leopard on a dual 450 MHz-equipped Power Mac G4 upgraded with 1 GB of RAM and a Quartz Extreme capable video card -- which is required for Core Animation and Time Machine -- and it seemed "to run a little faster than Tiger".

Keep in mind that MacOS X 10.5 "Leopard" does not support the MacOS 9 "Classic Environment" even when running on systems that support "Classic" when booting MacOS X 10.4 "Tiger". This may be a major disadvantage for some users.

Your results may vary -- this is a "hack" after all -- and it is not supported by Apple and consequently cannot be recommended by EveryMac.com. However, for machines that are not "mission critical", particularly ones that are near the 867 MHz cutoff point -- such as the Power Mac G4 733 (Quicksilver), 800 DP (Quicksilver), and 800 (QS 2002) -- and ones that have been upgraded with faster processors, more RAM, and Quartz Extreme capable video cards, you may find that these "unsupported" Macs provide more than acceptable performance running MacOS X 10.5 "Leopard".

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