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Home -> Community -> Mailing Lists -> Oracle-L -> FW: question about cpu usage
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
-----Original Message-----
From: Cary Millsap [mailto:cary.millsap_at_hotsos.com]=20
Sent: Friday, October 22, 2004 3:05 PM
To: 'ryan_gaffuri_at_comcast.net'
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
-----Original Message-----
From: oracle-l-bounce_at_freelists.org =
[mailto:oracle-l-bounce_at_freelists.org]
On Behalf Of ryan_gaffuri_at_comcast.net
Sent: Friday, October 22, 2004 2:56 PM
To: oracle-l_at_freelists.org
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
-- http://www.freelists.org/webpage/oracle-l -- http://www.freelists.org/webpage/oracle-lReceived on Sun Oct 24 2004 - 14:43:47 CDT
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