horrible disk thorughput on itanium

[Greg Hennessy]

I recently installed a  both a Dell dual cpu 2500 server (dual 1.6 ghz
ia32 chips) and a dell 7150 (dual IA64 chips). My users complained
that the disk io speed on the itanium seemed very slow, even though
both servers have a megaraid controller with seagate cheetah
disks. Bonnie also shows the ia64 machine having worse throughput than
the ia32 machine. 

[root@hydra bonnie]# cat bonnie.hydra bonnie.leo 
              -------Sequential Output-------- ---Sequential Input--
	      --Random--
              -Per Char- --Block--- -Rewrite-- -Per Char- --Block---
	      --Seeks---
Machine    MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU
/sec %CPU
          100  1765 100.0 282891 100.1 377295 100.0  2058 100.0 592709
	  99.5 51920.4 196.5
              -------Sequential Output-------- ---Sequential Input--
	      --Random--
              -Per Char- --Block--- -Rewrite-- -Per Char- --Block---
	      --Seeks---
Machine    MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU
/sec %CPU
          100 17049 100.1 265197 101.0 197094 98.2 16631 100.4 675831
	  99.0 40400.0 191.9

Hydra is the itanium, leo is the 32 bit machine. The character io of
hydra is a factor of 10 slower than that of leo. Is this more likely a
kernel issue, or a glibc issue? Both machiness run standard redhat
7.1, and 2.4.9-12smp kernels.