How much RAM do you have on this system? How much is actually allocated to SQL Server? How much is actually being used day-to-day? Before the dirty pages are written to disk, they are on buffer cache. If you leave all of them there for a day, you might run out of RAM. I would only recommend if you from time to time, command a checkpoint when necessary. But again, if your bottle-neck is on disk IO, it will not help the long run. Your eventual goal is to have the system run smoothly auto-piloted.