ThermographX

ThermographX is an excellent software application that carefully scrutinizes the temperature readings on your modern Macintosh G4 or G5. This software tool monitors the different temperature sensors residing in your computer, allowing you to maintain the optimal temperature levels. However, it is worth noting that the MPC7450CE/D Rev 5 errata from Motorola discloses that "The thermal assist unit (TAU) is no longer supported on the MPC7450, MPC7451, or MPC7441.". This means that you will be unable to measure the junction temperature of any system consisting of these processors, which currently include the "Gigabit" PowerBook G4 and the "2001 Quicksilver" G4 models.

Additionally, compatibility with some older Mac models such as the G4 Cube has been eliminated in Mac OS X 10.3.5. But worry not, as there could be a possible workaround to this situation. Therefore, with its impressive temperature-monitoring functionality, ThermographX is a highly recommended software application for Macintosh G4 or G5 users looking to ensure optimal temperature levels in their computers.