Without knowing more about your system, I'd guestimate that you have a SQL Server which is very busy. Lots of page reads and lots of page writes indicates this. This is either because you have tons of transactions going on, or because there are weaknesses in the database code, causing the server to be busy Reading and writing from/to disk. There are loads of suggestions to ease up your server's disk activity, but they all depend on what is going on and why it is going on. Looking only at disk activity is not enough.