wbmw,
SpecInt does not care about 64 bitness, database cares a great deal. SpecInt does not care about the amount of memory, database performance depends a lot on it (Itanium in your example has 2x memory).
In addition to these greatly unbalancing variables. In addition to these, the Itanium server has 2x controllers and 2x hard drives.
The problem with TPC-C benchmark is that you rarely if ever get to compare apples to apples.
Joe