i have got 32 Gig of Ram added to server that has SQL Server on it,

how much memory should be assigned to Sql and how much should be left for Wi

Hello,

It depends on the complete configuration of the server.

You should leave at least 4 GB for the OS to ensure it works smoothly.

Is it a dedicated SQL Server = no other server system running on the machine? Then you can assign the rest of RAM for the SQL Server, otherwise you have to consider how much workload are on the other server system.

Hi,

If 32 GB of RAM is added to existing server having sql server then sql server still won't be able to utilize the added RAM until it is being configured.

Assuming this being 32 bit server, you need to configure min and max memory settings. Leaving 4 GB for OS, the remaining you may configure for sql server if it is the only application that runs on that server else it will depend on the different workloads on that server.

Also you may need to enable AWE and add the sql server service account under lock pages in memory settings.

If it is 64 bit server , then you only need to set min and max memory. In 64 bit the memory is dynamically managed.

Hope this helps!!

Addition to above see-http://www.sqlskills.com/blogs/jonathan/how-much-memory-does-my-sql-server-actually-need/