I forgot to cc the list last Friday when I responded to this... Cary Millsap Hotsos Enterprises, Ltd. http://www.hotsos.com * Nullius in verba * Upcoming events: - Performance Diagnosis 101: 10/26 Toronto, 1/4 Calgary - SQL Optimization 101: 10/18 New Orleans, 11/8 Dallas, 12/13 Atlanta - Hotsos Symposium 2005: March 6-10 Dallas - Visit www.hotsos.com for schedule details... -----Original Message----- From: Cary Millsap [mailto:cary.millsap@xxxxxxxxxx]=20 Sent: Friday, October 22, 2004 3:05 PM To: 'ryan_gaffuri@xxxxxxxxxxx' Subject: RE: question about cpu usage Ryan, Good question actually. It depends on how many CPUs are in there. If you have a copy of "Optimizing Oracle Performance" handy, check out table = 9-3 on page 260. What it says is that you can expect performance to vary unpredictably on a 1-CPU machine when CPU utilization exceeds 50%. On a 2-CPU machine, the magic number is about 57.7%. On a 4-CPU machine, it's 66.5%. The table lists "knee in the curve" numbers for CPU counts = ranging from 1 to 128. The whole section called "Behavior of M/M/m Systems" (pp254-266) should = be of interest to you. Cary Millsap Hotsos Enterprises, Ltd. http://www.hotsos.com * Nullius in verba * Upcoming events: - Performance Diagnosis 101: 10/26 Toronto, 1/4 Calgary - SQL Optimization 101: 10/18 New Orleans, 11/8 Dallas, 12/13 Atlanta - Hotsos Symposium 2005: March 6-10 Dallas - Visit www.hotsos.com for schedule details... -----Original Message----- From: oracle-l-bounce@xxxxxxxxxxxxx = [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of ryan_gaffuri@xxxxxxxxxxx Sent: Friday, October 22, 2004 2:56 PM To: oracle-l@xxxxxxxxxxxxx Subject: question about cpu usage I'm not a hardware guy or sys admin person so forgive me if this is a = stupid question. Leaving out all other variables(such as IO), should I expect performance to be the same in a databse if the server it is riding at is = at 90% cpu usages as opposed to 10%? since there would still be spare = cycles? Or is there a declining returns as you get closing to the maximum = available cpu usage?=20 -- //www.freelists.org/webpage/oracle-l -- //www.freelists.org/webpage/oracle-l