Paging File Size

  • Thread starter Thread starter Gabe Matteson
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Gabe Matteson

With a 32-Bit machine, the server can address up to 4GB of memory correct? I
have 6GB of memory in the server with the /3gb and /PAE switch. With this
configuration, would I have need of a paging file since the max a program
can use is 4gb? (one program can use a max of 4gb correct?) If I do need a
paging file would i set it to 150% greater than 6gb so it would be 9GB? What
math do I need to figure out what a 64-bit machine can use for memory? what
is the equation? thanks
 
Nope,

The extra memory above 4GB will not be paged.

Be also aware that not all applications make use of the extra memory, even
between 2 and 3GB, namely:

2~3GB (/3GB):
The application (EXE header) must have the bit set: large memory aware (or
something like that).
4GB (/PAE):
Click to expand...
The application must make use of the AWE API.

Some examples:
Exchange: /3GB: yes, /PAE: no

SQL: /3GB: yes, /PAE: yes (Oracle as well)

AND: you have to tell the application to use that API (SQL: awe, Oracle: vlm)

The kernel will still use 1GB of virtual address space
So in short:
Kernel: 3~4GB (in case of /3GB)
Your app: 0~3GB (0~2GB if your app is not compiled that way, so 2~3GB will
then not be used)
and 4~6GB in case of /PAE, accessible by extra API only.

64bit: remember IA64 (Itanium) is not the same as x64). Furthermore, it
differs by version of Windows. Examples:
2003 Ent, Itanium: 64GB
2003 DC, Itanium: 512GB

Don't forget to check your application as well!

--


Chau chau,

Pascalos
 
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