T
Travis
I have XP Pro with 768MB of RAM. Recently I changed my performance
setting for XP from memory optimization for programs, to memory
optimization for system cache so that all the free memory would be
used for the cache instead of being unused. This effectively enables
the 'DiablePagingExecutive' and 'LargeSystemCache' registry settings.
Since doing this I've noticed something, maybe it was happening before
but if it was it is definitely worse. I typically leave my computer
with a half dozen programs open. While using the programs, I can
switch between them with virtually no disk access. However, when I
get up in the morning and start using the programs again, there is
initially a huge amount of disk access as I use it program again, even
though it was left open. It is as if XP determined these programs
were inactive since they had not been used for 10 hours or so.
Ideally, I want my system to always allocate free physical memory to
the cache until I open a new program in which it should reduce the
cache size to allow me to load the program in memory, but, also, I
don't want it to page memory used by open applications to the hard
disk, ever. In other words, the memory the applications are using
should be 'locked' and only paged to disk in the event there is not
enough free physical memory for all the open applications (in which
case it should page the memory of the application which is getting the
least usage, or 'oldest.)
Now someone might say just turn the performance setting from 'system
cache' back to 'applications'. But it is my understanding that when
this setting is active, XP only allocates a portion of free physical
memory for the cache and thereby if you have a machine with lots of
memory and your applications are typically only using about 30% of it,
you will have a large chunk of free physical memory that isn't being
used for anything when it could be used for the cache.
I also tried a program called O&O CleverCache. It appears to make no
difference in how the cache is allocated compared to just setting XP
in the 'system cache' performance mode. I even ran several Sandra
hard disk benchmarkers with the bypass Windows cache setting disabled
and see very little difference in drive performance when using it.
I still want to figure out how to prevent open applications from being
paged to disk after a long period of inactivity while still allocated
any free physical memory to the cache.
setting for XP from memory optimization for programs, to memory
optimization for system cache so that all the free memory would be
used for the cache instead of being unused. This effectively enables
the 'DiablePagingExecutive' and 'LargeSystemCache' registry settings.
Since doing this I've noticed something, maybe it was happening before
but if it was it is definitely worse. I typically leave my computer
with a half dozen programs open. While using the programs, I can
switch between them with virtually no disk access. However, when I
get up in the morning and start using the programs again, there is
initially a huge amount of disk access as I use it program again, even
though it was left open. It is as if XP determined these programs
were inactive since they had not been used for 10 hours or so.
Ideally, I want my system to always allocate free physical memory to
the cache until I open a new program in which it should reduce the
cache size to allow me to load the program in memory, but, also, I
don't want it to page memory used by open applications to the hard
disk, ever. In other words, the memory the applications are using
should be 'locked' and only paged to disk in the event there is not
enough free physical memory for all the open applications (in which
case it should page the memory of the application which is getting the
least usage, or 'oldest.)
Now someone might say just turn the performance setting from 'system
cache' back to 'applications'. But it is my understanding that when
this setting is active, XP only allocates a portion of free physical
memory for the cache and thereby if you have a machine with lots of
memory and your applications are typically only using about 30% of it,
you will have a large chunk of free physical memory that isn't being
used for anything when it could be used for the cache.
I also tried a program called O&O CleverCache. It appears to make no
difference in how the cache is allocated compared to just setting XP
in the 'system cache' performance mode. I even ran several Sandra
hard disk benchmarkers with the bypass Windows cache setting disabled
and see very little difference in drive performance when using it.
I still want to figure out how to prevent open applications from being
paged to disk after a long period of inactivity while still allocated
any free physical memory to the cache.