Memory size over 1GB

  • Thread starter Thread starter Charles Elliott
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C

Charles Elliott

I upgraded memory from 512 MB to 1024 MG, but WinXP rarely uses more that
one-half of it. I understood that with Win2K the O/S used different page
sizes for small and large memory configurations. Is that true with WinXP,
and if so, how can I get XP to use all 1024 of memory without re-installing
O/S?
 
Charles Elliott said:
I upgraded memory from 512 MB to 1024 MG, but WinXP rarely uses more that
one-half of it. I understood that with Win2K the O/S used different page
sizes for small and large memory configurations. Is that true with WinXP,
and if so, how can I get XP to use all 1024 of memory without re-installing
O/S?
Click to expand...
Run more programs at the same time ...

XP will do just fine all by itself with 1gig ram, leave it be. ;)
 
Charles

What did you expect?..

Upgrading from 512mb to 1gb will enable applications like Word to pop up a
little quicker, but if you are a 30wpm typist, then you will get 30 words
per minute regardless.. programs like Spybot and Adaware will check a little
quicker.. you will be able to open more applications at any one time, while
still maintaining some performance.. the Windows pagefile will not be
accessed quite as much as it may have been.. installing applications will be
quicker.. picture editing will not be so much of a pain..

It doesn't hurt to have large amounts of memory installed, but if your
general computing habits wouldn't have put much strain on 512mb, then
upgrading may have been a waste of funds..
 
Thanks for your reply.

I have several programs, such as Dragon Naturally Speaking 8 (DNS8) and and
Eclipse, that use well over 100MB of RAM. DNS8 in particular runs much
better with more memory.

Right now Task Mgr says that 436,072 bytes of memory is available and
586,522 is being used for system cache. Kernel is using 61,304 and the
commit charge is 442,088. I added up (by eyeball, not calculator) all the
program memory usage figures under the process tab in Task Mgr and got
442,000. But many processes are half or more paged out to disk. What I
expected is that memory available would be near zero before it started
paging processes out to disk.

Do you know if WinXP uses a different page size for large memory sizes (>= 1
GB) than for smaller amounts of memory like Win2K did? It makes a
difference in how the page tables are handled.

C Elliott
 
Charles

It is better to set Windows to manage its own pagefile size.. Windows will
always use a pagefile at some point, regardless of the memory installed.. it
is written to do that.. however, with more memory installed, it will access
the pagefile less.. I have 2gb memory installed, and although Task Manager
shows a 417mb pagefile size, the computer is not using it as can be seen by
zero HDD LED activity.. it is just there for when Windows decides to use
it.. even the mighty UNIX uses a pagefile.. it is not just Windows that
does..

The only instance that one might set a pagefile size is where a machine is
set to do just one task.. this is a not applicable to a computer that is
used for general tasks, as in the case of home users.. if you feel that the
pagefile is taking up too much space, get a larger hard drive.. do not try
to constrain Windows by setting a pagefile size that you think is adequate..
it will not improve performance..

You might want to take a look at this article..
http://aumha.org/win5/a/xpvm.php
 
The Pentium CPU has two RAM page sizes: 4096 bytes and 4 Megabytes. For
each page of RAM, there must be an entry in the page table, which itself is
pageable and in RAM. Hence for 2^30 = 1,073,741,824 bytes of main memory,
there must be 2^30 / 2^12 = 2^18 = 262,144 page table entries. That is a
huge table for the memory manager to have to search every 300 milliseconds
or so. So it is my understanding that Win2K uses a different scheme when a
large amount of memory is installed. However, swapping a 4 MB page to disk
is onerous too, so now I am not sure. The only way to get Win2K to use that
new scheme was to re-install the O/S. In any case my question of you was,
do you know if WinXP uses a different memory mapping scheme if the computer
has a large amount of memory installed than when it has a small amount of
memory? That question has nothing to with the size of the pagefile, which
for your information, it does not matter how big you make it; if XP needs
more, and more disk space is available, XP will take it.

Thank you for your time and effort!
 
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