OS CPU utilisation vs Sybase engine utilisation

[Former Member]

Hi,

   One of our Sybase servers(ASE15.7 ESD #1) running on AIX with 12 CPUs. Sybase engines also configured to 12.

   SCC monitoring shows sybase engines utilized 100% for sometime during EOD, However 'nmon' report shows only around 10 out of 12 CPU being used for the same time period. What are the possible reasons for this difference ? is it something ASE is not fully utilising assigned physical CPU ?

Thanks,

Raj

[Former Member]

Is nmon reliable? I see it is not supported by IBM.

http://www.ibm.com/developerworks/aix/library/au-analyze_aix/

Do you see the same behaviour if you assign 11 CPUs to Sybase and leave one for OS?