Better CPU's Same Workload - CPU Utilization Remains the Same...
From: Oracle Dba Wannabe <oracledbawannabe_at_yahoo.com>
Date: Fri, 16 Jul 2010 10:51:53 -0700 (PDT)
Message-ID: <63687.66595.qm_at_web113901.mail.gq1.yahoo.com>
Hi All,
We recently had a change in hardware, where servers that were about 4-5 years old (SUN) were replaced with new ones (HP) - processors with better speed. Generally on these old boxes (3 Node 10.2.0.4 RAC). CPU utilization was at about 85-90%. Now on these new servers (2 Node RAC 10.2.0.4), the workload remains the same based on AWR transactions per second, user calls, etc. However I notice with the new hardware, that the same SQL now spends less CPU time for example if a particular SQL took around .4 seconds it now takes .2 - this difference is seen through pretty much all SQL statements. The trouble is though, that the CPU utilization remains the same too on these new servers. Is it correct to think that with SQL queries using less cpu time that there would be more idle time than before and hence less utilization? Oh as, I wrote this I just realized, since we've gone from 3 nodes to 2 nodes - each box does more logical i/o than it used to - so perhaps this may explain why utilization has not dropped?
On a side note, this question isn't about what the best utilization is, or that I'd like to drop my utilization - Just trying to understand what's going on so I can explain to management why their new hardware is showing the levels of utilization that it is.
Thanks
Date: Fri, 16 Jul 2010 10:51:53 -0700 (PDT)
Message-ID: <63687.66595.qm_at_web113901.mail.gq1.yahoo.com>
Hi All,
We recently had a change in hardware, where servers that were about 4-5 years old (SUN) were replaced with new ones (HP) - processors with better speed. Generally on these old boxes (3 Node 10.2.0.4 RAC). CPU utilization was at about 85-90%. Now on these new servers (2 Node RAC 10.2.0.4), the workload remains the same based on AWR transactions per second, user calls, etc. However I notice with the new hardware, that the same SQL now spends less CPU time for example if a particular SQL took around .4 seconds it now takes .2 - this difference is seen through pretty much all SQL statements. The trouble is though, that the CPU utilization remains the same too on these new servers. Is it correct to think that with SQL queries using less cpu time that there would be more idle time than before and hence less utilization? Oh as, I wrote this I just realized, since we've gone from 3 nodes to 2 nodes - each box does more logical i/o than it used to - so perhaps this may explain why utilization has not dropped?
On a side note, this question isn't about what the best utilization is, or that I'd like to drop my utilization - Just trying to understand what's going on so I can explain to management why their new hardware is showing the levels of utilization that it is.
Thanks
-- http://www.freelists.org/webpage/oracle-lReceived on Fri Jul 16 2010 - 12:51:53 CDT