Why does Desktop Window Manager leak memory or even crash?

Question

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?

Hardware:

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

Edit:

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.

Answer 1

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.

Answer 2

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" = "4.09.00.0904"
• 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.

Answer 3

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.