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Argenis Fernandez

The Myth Around 32-bit SQL Server Instances on 64-bit Operating Systems, and AWE

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Published Sunday, December 30, 2012 4:36 PM by Argenis

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Greg Low said:

Great (and clear) post Argenis. Thanks for sharing it.

December 30, 2012 6:56 PM

Ian Yates said:

You're right about the bad documentation - a lot of bloggers don't consider x86 SQL Server on x64 Windows and neither does much of the Microsoft documentation.

We have been taking advantage of this for a couple of years on several customer sites because we need to integrate SQL with some legacy DBs via linked servers that only have 32 bit drivers. Enabling AWE at least lets us take advantage some of that RAM. Unfortunately other issues still exist such as bad backup utilities and DB drivers depleting the "memtoleave" area put aside for their operation in the x86 address space.

Great post 😊

December 30, 2012 7:00 PM

Greg Linwood said:

Nice post Argenis & Happy New Year to you too.

I like the way you posted the remaining columns in the dm_os_process_memory output as they reveal a few other interesting points.

Note that the process still has a Virtual Address Space even when using AWE? This is because only a couple of memory managers use AWE in SQL 2008 whilst many of the others use regular Virtual Memory. This is something that has changed in SQL 2012 so it would be interesting to see the same output from SQL 2012 vs SQL 2008.

Also, there is more physical memory in use than locked allocations. "In use" isn't exactly the same as "allocated" but the difference between these two is roughly what physical memory has been allocated to back the virtual memory. The relationship between all of these can also be influenced by other settings such as -g startup switch, which is also something you need to consider when using AWE under x86 SQL systems..

December 31, 2012 1:15 AM

Joseph said:

Nice article, Argenis!

January 2, 2013 10:26 AM

Tx Argenis said:

Simple & Clear

June 21, 2013 1:14 AM

Simple User said:


one quick question is it also possible for version:

Microsoft SQL Server 2008 R2 (RTM) - 10.50.1600.1 (X64)   Apr  2 2010 15:48:46   Copyright (c) Microsoft Corporation  Express Edition with Advanced Services (64-bit) on Windows NT 6.1 <X64> (Build 7601: Service Pack 1)   ?

May 13, 2014 3:46 AM

Argenis said:

Hi Simple User. SQL Server 2008 R2 Express is capped to 1GB of RAM, so AWE obviously out of the picture. Both more importantly, you're running 64bit SQL on 64bit Windows, so AWE doesn't apply to you at all.

May 13, 2014 11:44 AM

Simple User said:

Thank you very much for your answer.

So to make it clear - when I run SQL Server Express R2 on 64bit machine SQL will only use 1 GB RAM and I can't do anything about it?

May 20, 2014 7:14 AM

Argenis said:

May 20, 2014 12:46 PM

Roy Ogborn said:

Awesome post! Thanks for putting in the time to explain this well. One simple check box makes all the difference in the world.

June 19, 2014 6:27 PM

Simple User said:

Thank you very much for your reply and clarification.

June 24, 2014 4:01 AM

Rafael Goncalez said:

Hi Argenis, great post!

I'm just in doubt in one point. When you say: "I did not enable AWE. I did grant the “Perform Volume Maintenance Tasks” and “Lock Pages in Memory”", after enabling AWE do you remove the those permission? How do you handle it? I'm asking because I've read about potential performance issues letting those permissions enabled.

Thank you.

May 14, 2015 7:48 AM

Argenis said:

@Rafael, hopefully will clarify that you need Lock Pages in Memory enabled in order to leverage AWE. Lock Pages in Memory can cause performance problems indeed, but those are found typically on VMs where a memory reservation has NOT been made for the guest and ballooning takes place.

If on a VM, reserve memory, and you can lock pages in memory pretty safely - then leverage AWE.

May 14, 2015 7:32 PM

Rafael Goncalez said:

Thanks a lot for your complete reply. We have exactly that VM environment and your advice will be very helpful! Have a nice weekend.

May 15, 2015 9:20 AM

Ian Stewart said:

Why can't I get my 32bit version to use more than 3.7GB. I've followed the steps and restarted the SQL service. I have 12GB available. My specific version is...

Microsoft SQL Server 2008 R2 (SP2) - 10.50.4000.0 (Intel X86)   Jun 28 2012 08:42:37   Copyright (c) Microsoft Corporation  Enterprise Edition on Windows NT 6.1 <X64> (Build 7601: Service Pack 1) (WOW64) (Hypervisor)

July 30, 2015 12:13 PM

Argenis said:

@Ian - can you details steps you followed and associated ERRORLOG output on a post or something of that nature? A better medium for providing assistance than the comments section on a blog post.


August 3, 2015 11:49 AM

Ravi said:

All Same i install 32bit on 64 bit OS and meemory Consumpation takes near about 3239MB , Two days my application work superb but 3 morning i see my 300 employee can't logging bcoz the CPU is 99% only SQL server takes this 99% only.

may be this comes when i re-install in sql with 32 bit on my 64bit server. But in my previous days i installed 64bit SQL to 64Bit Server and that work very fine...

Now tell me is this MYTH is correcct or wrong..

March 14, 2016 11:07 PM

Argenis said:

@Ravi: Not sure I understand your comment. I didn't mention in my post that 32 bit instances of SQL Server perform better than 64 bit instances.

March 16, 2016 12:14 AM

Darrell said:

I have been using this setup for over 4 years, SQL 32-bit on Windows 2008 R2, 16GB-RAM.  I had issues today and found that the sqlserv.exe only allocated less than 200MB of RAM.  Yes, 200MB of RAM. When i disabled the AWE, it went up to 4GB RAM.  I enable AWE and set a MIN of 6GB and MAX of 14GB and the process still only shows ~108MB usage.  Any thoughts?

June 2, 2016 6:52 PM

Argenis said:

Hey Darrell,

How are you measuring memory usage?

June 9, 2016 2:27 PM

harveycole310245 said:

What I appreciate about you is that you admitted that you were wrong.

March 15, 2020 6:55 PM

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