XP File Caching Makes System Unusable

[Chandler]

While Windows XP is a good operating system in terms of stability, this stability is often ruined by the strange system cache behaviour.

If you look in Task Manager, the normal value for this is around 100MB, but I frequently see it grow to over 400MB, at which point programs are dumped to the page file to make room for it.

To me this seem counter-productive.  The whole idea of system cache is to reduce the number of disk reads, but by doing this it's making even more.  When it does hit the 400MB mark, everything becomes sluggish, even the mouse cursor (and free physical memory drops to around 2-10MB).

Is there any way to control this?  I never noticed it in Windows 2000 but all Windows XP machines I've seen do it to some extent.

I took one machine up to 512MB RAM from 256MB in hope to reduce the amount of pagefile usage, but this just seems to encourage XP to waste more memory with file caching.

[saoirse]

The Windows NT/2000/XP cache manager controls the maximum size dynamically, based on internal algorithms.  As far as I'm aware, this cannot be 'over-ridden'.  It's a pity.  I had always set a maximum 'vcache' with my 9.x systems.

You can look at the memory management settings in more detail here.

saoirse  

[Chandler]

Thanks for the link.

It's annoying because while on the most part the memory manager does a good job, it just occasionally goes nuts and starts using up all memory.

The way I see it is:
1) The cache should be allowed to grow to any size
2) But, if it reaches a size whereby programs are paged to disk, then it should stop caching new files, or discard the older ones from cache.

But as it is:
1) The cache is allowed to grow to any size
2) If it reaches a size whereby programs begin to page out to disk, it continues caching files until even Explorer is paged out (30 seconds for Start menu to appear now).
3) When memory gets incredibly low, Windows decides that it's dropped a <blank> and tries to do something about it.  Unfortunately at this point, it is creating even more Disk I/O than if it hadn't been caching in the first place!

Not at all good, especially when it comes to large Access databases.