Itanium has the lowest per-socket performance of all CPU families available NOW.


SPARCs you can buy NOW

As it turns out it's not SPARC that is lagging behind. With the release of quad core SPARC64 - VII half a year ago SPARC definitely beats Itanium on both per-socket, and maximum absolute performance basis.

http://www.sun.com/servers/highend/m9000/benchmarks.jsp#7

And this is high-socket-count turf, where Itanium should be strongest...

The technology behind SPARC64 - VII is also more modern; it has real SMT, OOOE, point-to point interconnections vs. Itanium FSB, and is clocked at 2.52GHz (65 nm). Also a lot of RAS is included.

http://www.fujitsu.com/global/services/computing/server/sparcenterprise/technology/performance/processor.html


POWERs you can buy NOW

It's Power6 - everyone knows it's faster than Itanium per-socket. It has best SMT, best memory bandwith, superior virtualization, highest clock rate etc. Consistently beats Itanium in all benchmarks with the same socket count.

Intel x64 you can buy NOW

Each socket in high-socket-count Intel servers can hold 6-core CPU (Dunnington). It's just 2 cores for Itanium, and that's a sad comparison. Not to mention a 1GHz clock difference.

Examples of Xeon being almost 2x faster per socket:

http://www.tpc.org/tpcc/results/tpcc_result_detail.asp?id=108081901

http://www.tpc.org/tpcc/results/tpcc_result_detail.asp?id=107061103

http://www.tpc.org/tpce/results/tpce_result_detail.asp?id=21
http://www.tpc.org/tpce/results/tpce_result_detail.asp?id=9


AMD x64 you can buy NOW

AMD sells quad core processors (double count of Itanium), with reasonable frequencies (>1GHZ above Itanium), and much more modern HT interconnect architecture and IMCs.

Eg.
http://www.tpc.org/tpcc/results/tpcc_result_detail.asp?id=108111701