Total amount of memory consumed (including AWE) by the buffer pool:

-- Total amount of memory consumed (including AWE) by the buffer pool:
/*

 Total Amount includes multi page allocator , virtual memory committed,shared memory committed and AWE
*/


SELECT SUM(multi_pages_kb + virtual_memory_committed_kb
+ shared_memory_committed_kb
+ awe_allocated_kb)/1024.00/1000.00 AS [Used by BPool, GB]
FROM sys.dm_os_memory_clerks
WHERE type = 'MEMORYCLERK_SQLBUFFERPOOL';