Sql Server max server memory

Question

 Hi,
 I know that , max server memory property is about physical memory limit for  buffer pool. But some says that, it is about Vas (virtual adress space) limit for buffer pool. I know that , Vas structure includes
physical memory and virtual memory. Then it means that max server memory is not equal max
physical memory for buffer pool.
Which one is true?

Answer 1

Both are true depending on the memory model your SQL Server is using
In conventional memory model. Max server memory is about memory limit for Bpool ( Bpool can be from RAM or Page file), so there is no guarantee that bpool will always be placed in physical memory it can be paged to page file when there is memory pressure.
In Lock pages and large pages memory model Bpool cant be paged and always placed in RAM so its limit for BPOOL in RAM
I assume you are referring  Page file as virtual memory and RAM as
physical memory
Read http://mssqlwiki.com/2013/03/26/sql-server-lock-pages-in-memory/ and http://mssqlwiki.com/sqlwiki/sql-performance/basics-of-sql-server-memory-architecture/ you will get clarity
Thank you,
Karthick P.K |My blogs|My Scribbles|Twitter|My Facebook
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