2 Itanium2’s v 4 Xeons?

I#%92m a BI developer and have a hardware question.

We have recently specked up some new servers for our datawarehouse and OLAP solution, we have opted to go 64bit. A consultancy suggested 4 dual core processors per box (around 3GHz Xeons) with 16gig ram. On presenting the consultants report to our hardware manager he has now kitted out the servers with 2 (1.6MHz) dual core Itanium2#%92s. Also, the boxes only have 2 sockets so there#%92s no room to expand in the future.

Without getting too caught up in what to do with the hardware manager what is the general consensus?

Generally speaking should 2 (1.6MHz 64bit) dual core Itanium2#%92s outperform 4 (3Ghz 64bit) dual core Xeons?

Any science or performance comparisons to demonstrate the case would be very much appreciated, mind you so would a yes or no.

see below as a starting point
http://www.sql-server-performance.com/forum/topic.asp?TOPIC_ID=15002

at the single core level,
Itanium 2 is probably equal or slightly behind the Netburt Xeon,
the latest Opteron is better,
and the Core 2 line (Xeon 51xx and 53xx) are tops
(above based on SPEC CPU)

Itanium shows strong advantage at high number of sockets,
definitely 16 and up.
Itanium has slightly better TPC-C at 4 socket dual core than Xeon 7140 (Netburst), which is a OLTP benchmark
there are no comparable TPC-H (DW) results
but I suspect that Itanium will be equal or below Xeon at 1-4 sockets

In any case, at 2 sockets, the quad core Xeon X5355 is the strong winner, both in top performance and bang for the buck

I am not a fan of buying a system with empty sockets, for room to grow.
buy what you need now,
buy a new system when you need to grow,
this is the best strategy for lowest total cost

The argument should probably be
buy the 2 socket Xeon X5355 now for development/QA prototyping large load handling assessment
if it turns out you need about 2X more power,
buy the 4 socket quad core when it comes out in the next quarter,
if it turns out you need 4X or more power
buy a 16+ socket Itanium system