Memoy Management under nt, w2k, xp / Caching

[=?ISO-8859-1?Q?Hans_M=FCller?=]

Hello,

for years now I wonder about the strange behavior of the file system
cache of the different flavors of windows nt (2k, xp).

If you copy large files via network or from disk to disk, windows tries
to cache all file operations. If your memory is full it swaps out
application data to get space for more cache memory. The result is that
you cannot use the computer while the copy is in progress.

Has someone a solution for this problem ?
Is it possible to limit the file cache size ?

If you would like to see it, try this:


1. Start some progs (perhaps a web browser, word processing software)
2. Transfer some big files (> 1G) to your hard disk from network. (using
ftp is faster and shows the problem better)
3. Wait a minute, do nothing
4. Then, while copying is in progress try to switch between the open
applications. This will be painful slow. If you have a fast network and
a not so fast hard disk (laptop) the pc will be completely out of
service until copying is finished.

Thanks a lot in advance
Hans

 

[Squire]

Hi, Hans,

The answer is not simple,
The CPU has to sort out and divide its time between several ongoing programs
all at the same time. Verifying each bit, and transferring correct data to
its destination. The more you throw at it, the harder it has to work and a
greater chance for errors.

A data stream gets broken into many parts when more than one program is
running, so data transfer is slower.
The Cache acts like a surge chamber in a hydraulic system, it takes the
overflow of data and feeds it back to the system as it can handle it.
The best thing to do when downloading or copying large programs, is just sit
back, get a cup of coffee and give it a chance to complete its mission.

Don't get an ulcer worrying about it.

Have a good day,
Jerry

Hello,

for years now I wonder about the strange behavior of the file system
cache of the different flavors of windows nt (2k, xp).

If you copy large files via network or from disk to disk, windows tries
to cache all file operations. If your memory is full it swaps out
application data to get space for more cache memory. The result is that
you cannot use the computer while the copy is in progress.

Has someone a solution for this problem ?
Is it possible to limit the file cache size ?

<Snip>