You are experiencing Rapid Recovery using an overwhelming majority of the memory on the Core machine (90%+).
By default, Rapid Recovery uses Windows write caching to improve performance of writes to the repository. However, in some core systems (primarily Server 2008) write caching may prove detrimental to performance as Windows is not able to properly keep up with the amount of cached writes. Hence the systems memory fills up with cached writes that are slowly being committed to disk. Once the memory is filled up all Core functions begin to operate slowly as they must struggle to acquire memory to perform tasks. By disabling write caching we improve the overall performance of the Core server by freeing up memory.
To resolve this issue, change the write caching policy.
To change the write caching policy for a repository to off and reclaim the memory that was being used:
Note: Please do not change the WriteCahingPolicy to 3 for the repository extension, that is residing on the storage with non standard bytes-per-sector value. The standard value is 512. Otherwise repository will not mount.
Windows Registry Disclaimer: