
 Understanding 64bit PowerPC architecture 
  Capable of addressing an astronomical 18 billion GB, or 18 exabytes, of memory, 64bit integers also accelerate complex mathematical calculations through their ability to perform calculations directly on 64bit numbers, as well as performing multiple operations on smaller numbers within a single CPU cycle (see Resources for the definition of exabyte). 
  To preserve the "power of two" relationships that people have come to expect, with 8, 16, and 32bit words in existing architectures, developers are getting 32 more bits, resulting in an address space that is 4 billion times larger than the maximum address space of a 32bit system. 
  The desktop and embedded industries needed another bit. 
 www106.ibm.com /developerworks/library/pamicrodesign/?ca=dgrlnxw0164BitPowerPC (3819 words) 
