RE: CPU upgrade,how much CPU usage reduction to expect?

The thing is, I'm utterly 100% confident that in spite of what you say, disk I/O definitely /is/ the bottleneck for /some/ user action, for /some/ time scope. (When I say "utterly 100% confident", I mean that I can prove it mathematically.) The question is whether that user action and time scope combination is one that your business really cares about.

It's a very important question to answer, and it's one reason why I think that focus on individual user actions is so important.

Why? Because upgrading CPUs is very likely going to make that thing take longer than it did before the CPU upgrade. :)

Cary Millsap
Hotsos Enterprises, Ltd.
http://www.hotsos.com
* Nullius in verba *

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-----Original Message-----
From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of zhu chao Sent: Thursday, April 15, 2004 9:17 PM
To: oracle-l_at_freelists.org
Subject: Re: CPU upgrade,how much CPU usage reduction to expect?

Hi, Dennis:

    We have just upgraded our storage, so disk io is not our bottleneck now.
As our server will have to support 2X capacity, we decided to upgrade CPU(in
fact, move to another server with 1.2G CPU,both of them are Fire880). Memory
is not bottleneck too, swap is not used on this server.

    I will post the result after the server upgrade.

Regards
Zhu Chao.

• Original Message ----- From: "DENNIS WILLIAMS" <DWILLIAMS_at_LIFETOUCH.COM> To: <oracle-l_at_freelists.org> Sent: Friday, April 16, 2004 12:10 AM Subject: RE: CPU upgrade,how much CPU usage reduction to expect?

> Zhu
> In general, a server tends to bottleneck on one of three components

--


> CPU, memory, or disk. For example, on a system that is bottlenecked on

the


> disk, upgrading the CPUs may have little effect on overall system

> performance. Naturally Oracle production systems with many users tend

to
be


> more complex than that. If you can determine which is your bottleneck,

then


> you may get an idea of what the difference in performance will be. A

good


> book that discusses these issues in some detail is Cary Millsap and

Jeff


> Holt's "Optimizing Oracle Performance". If your Oracle is

CPU-licensed,


> upgrading the CPU speed is a way to increase performance without

affecting


> your Oracle license. Just don't promise management that going from 900

to


> 1200-mhz will automatically make everything run 33% faster.

>


> Dennis Williams

> DBA

> Lifetouch, Inc.

> dwilliams_at_lifetouch.com

>


> -----Original Message-----

> From: oracle-l-bounce_at_freelists.org

> [mailto:oracle-l-bounce_at_freelists.org]On Behalf Of zhu chao

> Sent: Thursday, April 15, 2004 4:13 AM

> To: oracle-l_at_freelists.org

> Subject: CPU upgrade,how much CPU usage reduction to expect?

>
>


> Hi, list friends;

>     A capacity planning job.

>     Currently we have a server running 900MHZ*8 Sun Fire880. Peak CPU

usage


> is 60%(User+SYS). We will upgrade our CPu from 900MHZ to 1.2G HZ. And

we


> expect to see some CPU usage reduction, so that we can support more

users


> and more traffic.

>     And we will also replace a 450MHZ*12CPU E4500 with a 900MHZ*8

Fire880.


>     According to computer theory and your experience, how much cpu

reduction


> can we expect?

> Thanks;

> Zhu Chao

>


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