Why isn't my SQL Server taking full advantage of all the RAM I have available in my server?

Answer

SQL Server will only use up physical RAM if it really needs it. It won't automatically use up all of the available RAM. It appears that your server has more than the necessary amount of RAM it needs to run efficiently. Because of this, it isn't being used. Of course, as your server gets busier, or your database gets larger, you will find that SQL Server will automatically begin to use up more of the available RAM. It is always better to have too much RAM, than too little.