invisible

Different sources claim variously that the total size of the page file
allocated should be between 1x and 2x the size of your physical RAM. I've
always wonered why... surely if you have more real memory, should should
need *less* virtual memory... can someone explain this to me?

Thanks.

yor suiris

You want your page file to be big enough that the entire contains of the RAM
can be switched to/from the paging file.
--
Yor Suiris
Remove NOT to reply.
But it is best to share with the group.

invisible

RAM


I see... so there's a 1-to-1 correspondence between each byte of RAM and a
byte somewhere inside the page style? (Rather than only allocating space for
the data that actually gets swapped out...) Is that about right?

I presume this is for performance reasons...

Thanks.

helmut p. einfalt

Basically, WinNT allocates a certain minimum and a certain maximum for
swap file size, dynamically changing the swap file size according to
requirement. While the idea sounds quite intriguing (only the space
actually needed is used), reality isn't as bright as it should be:
-- By default, NT uses the C: disk for swap. And that's the one
that is most heavily used in the first place
-- The default swap drive C: is the one most likely
to be most fragmented of all available disks
-- Expanding and contracting the swap file takes more time
than just writing to a specified allotted space
-- Every expansion and contraction of the swap concurs with
file re-writes, slowing down the machine.

The issue is best addressed by:

-- making sure that there is a permanent swap file
(min = max) plus a 12-15 MB swap file on the C: drive
for memory dumps if required
-- moving the swap file either to
(a) a dedicated drive of 1.5-2 times RAM size,
preferably on its own controller (if SCSI), or
(b) a dedicated partition on the fastest drive, or
(c) a dedicated partition on the least used drive, or
(d) a permanent swap file on the least used drive or
partition
-- If running other swap-intensive applications who do their own
swap file management (e.g., Photoshop) make sure that these
have a swap drive/partition/directory of their own.

HTH

Helmut