Now that Intel has declared that "clock speed doesn't matter" (March 2004 - http://www.eweek.com/article2/0,1759,1551741,00.asp this is a good introductory article on the benefits of a 64 bit architecture. It discusses IBM's power management techniques. Includes a large number of reference links also. http://www-106.ibm.com/developerworks/library/pa-microdesign/?ca=dgr- mw2864BitPowerPC T.T.F.N. William H. Magill # Beige G3 - Rev A motherboard - 768 Meg # Flat-panel iMac (2.1) 800MHz - Super Drive - 768 Meg # PWS433a [Alpha 21164 Rev 7.2 (EV56)- 64 Meg]- Tru64 5.1a # XP1000 [Alpha EV6] magill at mcgillsociety.org magill at acm.org magill at mac.com whmagill at gmail.com