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Re: Oracle 10g on Windows 2003 x64 Memory Useage

From: Charles Hooper <>
Date: Fri, 10 Aug 2007 04:28:46 -0700
Message-ID: <>

On Aug 9, 6:14 pm, "Paul Linehan" <plinehan__A_at_T__yahoo__D.OT__COM> wrote:
> Charles Hooper wrote:
> > Have you enabled large page support on Windows and Oracle, which
> > causes Windows to use 4MB memory page sizes rather than 4KB memory
> > pages? If so, I suspect that Performance Monitor is showing incorrect
> > information. I am running Oracle on Windows 2003 x64, total
> > page file size for all drives is configured at 3124MB, yet Task
> > Manager reports that PF usage is 13.3GB. In my case, system
> > performance is great, so I am not too concerned about the inconsistent
> > numbers.
> > Have you verified that the page file is actually 10GB in size?
> I have read quite a few of your posts and I think
> that:
> a) you know what you're talking about
> and
> b) you genuinely try to help people.
> I hope that this info can help you and/or others.
> For Windows, there is a nifty/cool/rad/awesome(for Yanks
> only) - (choose term which hasn't gone out of fashion, or
> better yet, the one which has come back into fashion!!)
> Go towww.sysinternals.comand go for procexp (process
> explorer).exe - it gives more reliable results than
> the Windows performance monitor.
> Inconsistent numbers should not happen. The site also
> has a number of other useful bits and bobs for anyone
> concerned with performance.
> Paul...

Thanks for the suggestion - I have not experimented with that utility in quite a while.

Looking at the page file on the hard drive, it is currently at 3,199,488KB, with an upper limit hard coded at 4,092MB (4,190,208KB).

Process Explorer:

Commit: 13.6GB (roughly   14,260,634KB)
Commit charge current:    14,254,748KB
Commit charge peak:       18,208,828KB

(recorded roughly 60 seconds after the above) Task Manager:

PF Usage: 13.5GB (roughly 14,155,776KB)
Commit charge total:      14,258,808KB
Commit charge peak:       18,208,828KB
Physical memory total:    16,772,124KB
  "       " available:     3,798,000KB

Comparing the numbers between Process Explorer (now a Microsoft product) and Task Manager on Windows 2003 x64 are very consistently inconsistent.
- 3,798,000KB

 12,974,124KB physical memory in use
+14,254,748KB page file in use

 27,228,872KB total memory usage


 12,974,124KB physical memory in use
+ 3,199,488KB actual page file size

 16,173,612KB total memory usage

I *suspect* that the problem has to do with the memory page size being 4096KB for applications using large page support, rather than the expected 4KB memory page size. There is probably a bit of code in Windows that does not yet recognize the change (this is a new feature for Windows), either that or Microsoft should patent the approach of jamming 14,254,748KB of data into a 3,199,488KB file. :-)

Charles Hooper
IT Manager/Oracle DBA
K&M Machine-Fabricating, Inc. Received on Fri Aug 10 2007 - 06:28:46 CDT

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