Tim said:
I know I posted this a couple of days ago but I have not had any reply so...
I have 1GB of DDR3200 memory on a 2.8c Pentium 4 machine.
The performance tab on the task manager says that only about 250 MB of the
physical memory is in use and that there is usually about 180 - 200 MB
virtual memory used.
Is this healthy memory usage because I would have thought that it would be
better to use as much physical memory as possible (if the virtual memory was
not used the total physical memory would only be about half used up)?
Here is the reply that I posted to your first message:
*****
Windows XP will always use physical RAM rather than virtual memory for
all actual RAM usages.
What it does map to virtual memory is the unused portions of memory
allocation requests and these can be quite extensive.
Application programs and Windows components typically ask for memory
allocations that are larger than what they normally use. This is due
in part to provision for seldom-used portions of the code such as
error recovery procedures and also partly to a generally conservative
"play it safe and ask for a bit more" approach by programmers.
By definition. the memory manager must allocate sufficient memory
address space to each and every memory allocation request that is
issued. In order to maximize the effective use of RAM Windows XP only
allocates RAM addresses to those portions of the request that are
actually used. The unused or excessive portions are mapped to
locations in virtual memory. Note that this mapping only requires an
entry in the internal memory tables maintained by the CPU. No actual
disk activity is required because there is nothing to write to the
disk.
And if a previously unused portion of a memory request should suddenly
be required to be used then the memory manager can instaneously remap
the assignment of that item from virtual memory to an available
location in RAM
Hope this explains the situation.
****
Ron Martell Duncan B.C. Canada
--
Microsoft MVP
On-Line Help Computer Service
http://onlinehelp.bc.ca
"The reason computer chips are so small is computers don't eat much."
