My Desktop Window Manager memory usage keeps spiking and causing it to disable Aero, saying it ran out of allowed memory. DWM restarts and comes back up fine when I kill its process. Why is this happening? How can I correct it? Can I change the amount of memory it's allowed?

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  • Intel Core 2 Quad / EVGA 680i mobo
  • 8GB Patriot DDR2
  • (3x) Sapphire ATI Radeon HD 4760 (multi-mon setup, not Crossfire setup)


New system. Now on an AMD Phenom 2 1055T with 16GB DDR3. Same install of Windows 7 and same video cards (Though the new mobo, an MSI nf980-g65 also has onboard HDMI, which I'm now also using). Same exact issue.

I find it happens more often when I have browser(s) open, and when I have Seesmic (A Silverlight out-of-browser application) open.

  • Using the latest drivers ?
    – Sathyajith Bhat
    Nov 18, 2010 at 18:11
  • Latest directly from AMD/ATI, yes. I don't update video drivers via Windows Update because my experience shows that results in BSODs.
    – tsilb
    Nov 18, 2010 at 19:40

5 Answers 5


The official unofficial explanation from Windows Engineering team on this this is that Windows is pinning GPU Accelerated applications to your primary video card. The engineering team describes it as a "very inefficienct" to use a GPU Accelerated app on a non-primary video card.

They are very dismissive of the fact that this worked for many years and now all GPU rendering applications run a high risk of taking down DWM.

They know of no fix and claim no repro despite the repro being simple. Running multiple video cards in a non-SLI/Crossfire fashion and outputing to multiple monitors. Then moving a semi-active GPU accelerated application to a non-primary video card and monitoring the shared memory GPU allocations. They will spike relative to the activty of the GPU API for the application. Simply scrolling or typing in a GPU accelerated browser (Chrome, IE, Firefox) and you may run the risk of DWM allocating more GPU Shared ram faster than it can release it.

There may be issues surrounding reproing that perhaps are a combination of a ratio of Video Card ram to System Ram, however I can verify the GPU Shared memory spikes on ANY system with multiple video card setup. Whether it takes down DWM.

DWM has a resource usage kill switch that kicks in when it exceeds a resource allocation relative to your machine. I am unsure if systems with more system RAM or systems with more GPU ram are more susceptible as quite often memory allocations are padded relative to your RAM. Start up 10 applications on 3 nearly identical systems but differing RAM amounts and you'll get different memory consumption.

Again the official unofficial response to resolve this is - there is no solution and you should not run multiple video cards in a non-SLI/Crossfire setup.

Disabling GPU Acceleration on the browser also works. IE9 is the only browser I'm aware of where disabling GPU Acceleration results in fairly decreased performance.

Of course this issue also forces one to be very careful of where you run Flash/Silverlight/Movies. On my setup it's pretty much suicide to run any of those on my 2nd video card despite it being the exact same as my primary one.

  • 2
    Hello and welcome to SuperUser. Do you have any information source you can share with us? Feb 28, 2013 at 17:57
  • 2
    I actually got curious back in Oct of 2011 and e-mailed a few people @ Microsoft. Surprisingly got a response back from Steve who works in the graphics (as in video card/gpu/wdm) dept of Windows Dev and that was an excerpt from his explanation.
    – MDR
    Mar 1, 2013 at 5:35

First, I assume you're running a 64 bit version of Windows, or else, most of the 8GB are useless :)

Second, I would check what have you installed lately that integrates with Windows explorer. E.g., TurtleSVN (SVN integration piece) that I've witnessed misbehave many times. Essentially, it enumerates every folder you touch in explorer, anticipating the need to integrate it with an SVN repository. And sometimes that causes slowdowns and leaks - in Windows Explorer memory space.

Third, try to find out what else loads into your explorer memory space (use Process Explorer) and eliminate the real culprit. Another thing you can do is boot into safe mode and see if the problem occurs there as well.

Fourth, do not rule out a virus or malware - check thoroughly for any of those.


We ran into this specific situation very recently, specifically in the case of windows on a secondary GPU, very easily replicated on several machines. This is an incredibly specific corner case, but I'm willing to bet it applies to you.

Have the video cards in this machine ever been upgraded? If so, this is probably an artifact of previous DirectX configuration; Windows appears to not follow the correct upgrade paths from DX9 in every situation, and will instead try to run software emulation of newer features ("10Level9" they call it) which can cause undue load in dwm with hardware accelerated features, for instance Aero, on secondary GPUs.

The fix that worked for us as follows:

  • Launch regedit. (You can just search it out on the Start Menu in Win7).
  • Navigate to: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\DirectX
  • Check to see if "InstalledVersion" = "00,00,00,09,00,00,00,00" and "Version" = ""
  • If that's the case, delete the ENTIRE "DirectX" key. (If it's not, I may be barking up the wrong tree. Windows 7 should show 6.01.something though)
  • Reboot the machine, and the problem should be resolved.
  • It did indeed say 9.00...4.09... Went ahead and deleted that key, but I have way too much stuff open to reboot now. Will let you know what happened when I get around to my monthly update reboot :)
    – tsilb
    May 13, 2011 at 4:09
  • Thanks, I'll be interested to know. I actually found out after writing this that we had one machine it didn't make any difference on (but the image on that machine is a mess so there very well may be complicating factors). Worst case, it won't HURT though.
    – Shinrai
    May 13, 2011 at 6:14
  • It hasn't come up as often since that change, but it still does once in a while, even when nothing is running on the secondary adapters except Outlook and Remote Desktop.
    – tsilb
    Mar 19, 2013 at 17:26

Due to this (old) forum post being a top google search result for this problem, I am providing an update.

I am running Windows 7 x64 with two ATI video cards and 3 monitors. Simply typing text into Chrome on a monitor connected to the secondary video card causes dwm.exe memory usage to spike and Aero to be disabled.

After trying MANY proposed solutions, I was able to work around the issue by setting the "GPU compositing on all pages" to Disabled in the about:flags Chrome configuration screen.


I had the same problem and found the registry was off as suggested by Shinrai. However, removing that alone did not fix my problem. I also installed Direct X 11 from here, and that seemed fix the problem.

  • 1
    That link goes to a Powerpoint presentation.
    – tsilb
    Jul 21, 2011 at 22:26

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