The IIS Object Cache is part of the working set of the Internet Information Server process in physical memory. The objects stored in the Object Cache are related to objects in the operating system's nonpaged memory pool. The Object Cache can be paged to disk if memory is not sufficient to support a large enough working set for the Internet Information Server process. It is important to provide enough physical memory to maintain the Object Cache in the working set.
As you might expect, the size of the IIS Object Cache affects its performance. If the cache is not large enough, the system will have to retrieve the objects from disk. If the cache is too large, it will waste space in memory. By default, Internet Information Server allocates 10 percent of physical memory to the IIS Object Cache. This is an optimal size for most configurations. You can change the amount of physical memory allocated to the IIS Object Cache by entering a new value in the MemoryCacheSize value entry in the Registry.
For more information on changing the MemoryCacheSize value entry, see Regentry.hlp, a Registry help file on the Supplement 1 CD. MemoryCacheSize is also described in the online Windows NT Server Microsoft Internet Information Server Installation and Administration Guide.
You can measure the size and effectiveness of the IIS Object Cache by using Performance Monitor.