From Dave Kearns' directory lookup benchmarking figures:

Eliminating the quad x64 machine left the remaining four with the following "entries per second" returned:

* 25,941 for the dual 2.2-GHz Opteron. 
* 15,677 for the dual 1.5-GHz Itanium II.
* 3,482 for the dual 733 Mhz Itanium I.
* 3,560 for the dual 2.4 GHz Xeon.

That's right, the x64 was more than one and a half times faster that the Itanium II and a whopping seven and a half times faster than the Itanium I! For database work - and, after all, a directory is simply a special case of a database - these new machines are really going to rock. Start trying to get them into your budget just as soon as possible.

Read the full article here.