Wrong. When you use (otherwised unused RAM as disk cache), you have 4 situations: 1) You open an app that is cached. This is massive speedThis takes virtually no time.up compared to accessing disk. 2) You open an app that is not cached. The OS clears out some room in the RAM (almost instantaneous), and loads from disk. This is no slower than the case where you had no cache. 3) An already running program requests more memory. Disk cache containing programs that are not running can be safely discarded to make room for the program requesting additional memory. This takes virtually no time. If you do not have enough room in your disk cache and have to go to disk to get memory, you do not have enough physical memory anyways. 4) An already running program discards its reserved memory. The OS repopulates the memory with disk cache data while the disk is idle. This again has no negative effect on performance. As you can see, disk cache (aka SuperFetch) can provide only performance increases and it also fills the RAM up with "crap". The Windows 7 OS itself without any of its caching technologies don't take up that much RAM, so your performance issues lie elsewhere in the OS.