Patched kernels on HPC servers to 2.6.18-238.1.1.el5; All went fine except for the head node which has an issue with latest kernel (dies at boot with a kernel panic) so booting it into older version 2.6.18-194.1.1.el5 until we can sort this out.
Fixed an issue with openmpi on grid cluster - usual problem with openmpi.conf looking for Infiniband
Investigated unexpected computation speeds for differing chips with MPI. Slower CPU cores were completing jobs in less time than faster CPUs however this seems to boil down to the nature of the jobs, large array computations, the size of the CPU cache and the communication latency between parallel processes.
Some interesting links to Intel CPU types:
List_of_Intel_microprocessors
Comparison_of_Intel_processors
Intel_Cores