64-Bit CPUs: What You Need to Know

In this first of a three-part series, we'll take you from the genesis of IA-64 through the present day of Itanium, to the future: McKinley, Madison, and Deerfield. Then on to Hammer, PowerPC, SPARC, and more.

Its the peak, the top, its the Mona Lisa. Its the $64,000 Question: what processor will dominate 64-bit computing? Sixty-four bits holds the promise of new performance, new architectures, new compilers, and a new balance of power in CPU realpolitik. A clean break with the old, a new chance for the new.

What hardware or architectural changes are in store for 64 bits? Quite a lot, although few of them have to do with 64-bittedness, per se. But 64-bit processors are at todays very high end, and they showcase all the best thinking in microprocessor design. This is the cutting edge, where silicon manufacturing, computer architecture, compiler technology, and marketing wizardry all come together. In the words of Calvin and Hobbes, scientific progress goes "Boink!"

For most of us waiting breathlessly on the sidelines, the 64-bit battle is between Intels IA-64 and AMDs Hammer architectures. Separately, well evaluate the pros and cons of the "other" 64-bit processors used in workstations and servers, such as SPARC, Power, MIPS, and Alpha.

In this first segment of our 64-bit computing series, well launch into the wonder that is IA-64. Youve probably seen much information already written about Itanium and IA-64 architecture in the past few years, which is mostly a replay of Intel-generated information. Well try to get beyond the standard facts and hype, and take a critical look at Itanium and IA-64/EPIC, by describing features and delivering some critical analyses. Well set the stage for an architectural comparison with Hammer and other 64-bit architectures in future segments.

To be clear, this 64-bit computing architecture series is not performance testing focused. Its architecture focused, and discusses long-term potentials. We will, however, point you to a few Itanium performance studies on the Web.