High Quality Content by WIKIPEDIA articles! The iMac G5 was a series of desktop Macintosh computers designed and built by Apple Inc. using the PowerPC chip architecture. It was the last line of iMac computers that used a PowerPC chip, making it the last of the iMacs that could run Mac OS 9 (Classic) applications. In August 2004, the iMac design was overhauled. By this time, the PowerPC 970 chip had been released and was being used in the Power Mac G5 line. Famously, the Power Mac G5 needed multiple fans in a large casing because of the larger heat output from the PowerPC 970. Apple`s new iMac design managed to incorporate the PowerPC 970 into an all-in-one design with a distinctive form factor. The new design of the iMac used the same 17 and 20-inch widescreen LCDs, with all of the main logic board and optical drive mounted directly behind the LCD panel; this gave the appearance of a thickened desktop LCD monitor.