On 24 Feb 98 at 20:34, Kunal Ganguly wrote:

> normally, the optimal level for any computer with 32-256 megs of ram is 25%
> for the ram..
> for example if u had 32 megs of ram then a swap file of size 8 megs is quite
> sufficient....
> stress on the word 'sufficeint', in case u do heavu multitasking and/or have
> lots of proggies loaded at the same time, a swap file size equivalent to the
> ram size is more than what u need..

  This may, just possibly, have been appropriate under 16-bit
Windows.  It's clearly inappropriate for Win32.

  Unless you have disabled virtual memory, when a Win32 app obtains
memory from the operating system, the memory is associated with
"backing store" on a drive somewhere.  Code will normally be backed
by the associated .EXE or .DLL file; data will be backed by some
region of the swap file, which may grow at this point.  [There are
special cases where a DLL must be backed by the swap file, and an app
*may* chose to back some data with some specific (may be temp?)
file.]  This means that data memory allocation will fail when it is
made, if there is insufficient swap space available, rather than
scrambling around for space when a swap must be made.

  The problem with this "rule" you've suggested is that attempts to
start applications or to open files/documents are likely to start to
fail, because of insufficient swap file space, while there is still
plenty of unused real RAM.
  Even despite the "bloating" of some modern software, setting the
swap file to less than the size of RAM is taking a chance; you might
as well turn off virtual memory entirely.  And if you like setting it
to less than half the size of RAM, you have far more RAM than you
need, and might even consider selling some.

  Calculating swap file size on installed RAM size really only works
if you assume that the installed RAM size has been tailored to actual
use, which is the real determiner of swap file needs.  And if you
make that assumption, 25% cannot possibly be enough.

David G