 Famously, the Power Mac G5 needed multiple fans in a large casing (or else liquid cooling, an innovative solution Apple adopted for the highest-end Power Mac G5s) because of the high heat output from those CPUs.Apple's new iMac managed to incorporate the PowerPC 970 into an all-in-one design with a distinctive form factor.The computer used the same 17 and 20-inch widescreen LCDs found in the iMac G4, with the main logic board and optical drive now mounted directly behind the LCD panel; this gave the appearance of a thickened desktop LCD monitor.