You won't get a true picture of memory usage from Task Manager if the account the service is running under has the lock pages in memory privilege (edit: as per Mark Rasmussen's comment/link). To determine how much memory is being used you can look at:
- SQLServer:Memory Manager\Total Server Memory perfmon counter
- DMVs
I can't recall if there is a DMV or combination of that will give you the total memory allocation but the following will show the bulk of it.
SELECT TOP(10) [type] AS [Memory Clerk Type], SUM(single_pages_kb) AS [SPA Mem, Kb]
FROM sys.dm_os_memory_clerks
GROUP BY [type]
ORDER BY SUM(single_pages_kb) DESC OPTION (RECOMPILE);
SELECT DB_NAME(database_id) AS [Database Name],
COUNT(*) * 8/1024.0 AS [Cached Size (MB)]
FROM sys.dm_os_buffer_descriptors
WHERE database_id > 4 -- system databases
AND database_id <> 32767 -- ResourceDB
GROUP BY DB_NAME(database_id)
ORDER BY [Cached Size (MB)] DESC OPTION (RECOMPILE);
The second is the most interesting usually, buffer pool allocations by database. This is where the lions share will be used and it can be useful to understand which of your databases are the biggest consumers.
You say you enabled AWE on SQL Server but did you activate /PAE in the boot.ini file?
PAE enables Large Memory support.
Activate PAE in Windows 32Bit Enterprise
c:\boot.ini
[boot loader]
timeout=30
default=multi(0)disk(2)rdisk(0)partition(1)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(0)partition(2)\WINDOWS="Windows Server 2003, Enterprise" /fastdetect /PAE
http://support.microsoft.com/kb/283037
Lock Pages in Memory
As part of enabling AWE, you would also need to give the SQL Server Service user the right to Lock Pages in Memory. Enabling this option in the Group Policy dialog (gpedit.msc), prevents Windows from paging memory out of the SQL Server working set for its own needs, especially if memory starts to run low on Windows.
http://msdn.microsoft.com/en-us/library/ms190730.aspx
Monitoring AWE Memory Usage
To test AWE usage, I setup a Windows 2003 Enterprise SP2 with PAE enabled in boot.ini. I used SQL Server 2005 32bit Standard SP4.
The total physical memory is 8192Mb. The max memory setting for SQL Server is configured at 8192 and the minimum is at 2048.
Does SQL Server see AWE on startup.
2012-02-09 07:27:51.35 Server Address Windowing Extensions is
enabled. This is an informational message only; no user action is
required.
Is SQL Server using Locked Pages for the Buffer Pool
According to some blogs, I should be seeing this message, but I'm not.
Using locked pages for buffer pool.
This is an informational message only; no user action is required.
Memory being allocated through AWE
SELECT SUM(awe_allocated_kb) / 1024 AS awe_allocated_mb
FROM sys.dm_os_memory_clerks ;
[3648]
Memory allocated to Multi-Page memory.
select sum(multi_pages_kb)/1024 as [MultiPage Memory, MB] from sys.dm_os_memory_clerks
[14]
Multi-page memory can not use AWE allocated memory
Memory being used outside the buffer pool
SELECT sum(multi_pages_kb
+ virtual_memory_committed_kb + shared_memory_committed_kb) AS
[Memory used outside BPool, mb]
FROM sys.dm_os_memory_clerks
WHERE type <> 'MEMORYCLERK_SQLBUFFERPOOL'
[24]
Overall memory allocation by component
SELECT type, (single_pages_kb)/1024 as Single_Pages_MB, (multi_pages_kb)/1024
AS Multi_Pages_MB, (awe_allocated_kb)/1024 as AWE_allocated_MB
FROM sys.dm_os_memory_clerks
GROUP BY type
ORDER BY 2 DESC
This will show you how single-page and multi-page memory is being used by each component. It will also tell you which one is able to benefit from AWE.
Mutli-page : when request exceeds 8Kb
Single-page : when request is less than or equal to 8Kb
As a side note, I have found sp_whoisactive very helpful in finding slow queries, memory hogs and just about everything that's going on in SQL Server. Here is a link that Brent Ozar provides on how to set it up and use it.
http://www.brentozar.com/archive/tag/sp_whoisactive/
Best Answer
Standard Edition is limited to a 64 GB buffer pool.
To use all the available memory of the server, you'll need to upgrade to either Enterprise or Datacenter Edition, or scale out to multiple instances of Standard Edition.