Symptom

More and more RAM is taken for FileCache. This can, especially on x64 systems, impact performance of the system.

Explanation

While in x86 systems, the maximum is limited at 1GB for the SystemFileCache, in x64 systems, the limit can be larger than the installed ram. There is a detailed BLOG post discussing the issue here.

Workaround

Unfortunately, to set the limits, you have to use the Windows API. So either, if you have access to Visual Studio, you make yourself a little console application using the SetSystemFileCacheSize function (see here for MSDN Library entry) or you can search on the internet for "SetSystemFileCacheSize". There are a few freeware tools out there (e.g. here).

Comments

The API sets the limits for the running session. If you reboot, the limits are lost again. So if you want to set the limits without the need of user intervention after a reboot, make a planned task with trigger "At system startup".