on the AIX level.

Gatherer statistics :

sar -u : gives you an idea about the cpu usage
> % idle
> % waiting for i/o. If high, how come ?? ( full table scans, paging ??? )
==> CPU problem ? waiting for i/o problem ?

sar -q : gives you an idea about the run queue
> if run queue is high, it means you have a cpu problem. ( may be cause by high waiting for i/o )

vmstat : Is there paging ? ( generates high waiting for i/o )

vmtune : using vmtune you can see if your system is trying to use memory from the file cache. If so, the AIX starts paging.

Is the dbsnmp daemon of 7.x started. If so, it's possible it consumes a whole cpu for 100%. There's a patch available.

Do you have nmon ? It's a utility you can install to see how the system is performing. ( cpu, disks , adapters , processes,... ) If not, let me know you email adress. I will mail it.

Hope this helps
Gert