There are no hardware platform requirements beyond those required by AIX 7 or AIX 6.
AIX Enterprise Edition ships with AIX V7.1 at a minimum level of Technology Level 0 or AIX V6.1 at a minimum level of Technology Level 6.
AIX Enterprise Edition will run on IBM Power™ Systems based on the POWER4™, PowerPC® 970, POWER5™, POWER6® and POWER7® processors.
Although there are no other prerequisites many of the features of AIX Enterprise are designed to support clients that are using PowerVM™ virtualization technology.
Many of the capabilities of AIX Enterprise edition are available for AIX V5.3 with the IBM Systems Director Enterprise Edition