The first Itanium processor (codenamed Merced) was released in May 2001. Merced had 2MB or 4MB cache and a speed of 733MHz to 800MHz. The CPU FSB ran at a double-pumped 133MHz (commonly miscalled 266MHz), yielding 2.1GB/s raw bandwidth.

The second generation was codenamed McKinley and branded as Itanium 2. They shipped in June 2002. McKinley had 1.5MB or 3MB cache and a speed of 900MHz to 1GHz. The CPU FSB ran at a quad-pumped 200MHz (commonly miscalled 800MHz), yielding 6.4GB/s raw bandwidth.

The next ia64 processors released were codenamed Madison and also branded as Itanium 2. They were released in June 2003. Madison came in 3 flavours; 3MB cache at 1.3GHz, 4MB cache at 1.4GHz and 6MB cache at 1.5GHz. Its FSB was unchanged from McKinley, also 6.4GB/s.

Two new processors were added to the Itanium 2 family in September 2003. The first was a new Madison flavour with 1.5MB cache clocked at 1.4GHz and the second was the Low Voltage model (codenamed Deerfield) with 1.5MB cache at 1GHz.