csrss.exe using gpu, no dwm.exe

[Keyes]

I have two csrss.exe processes running under SYSTEM, which both have a con host peocess for an nvidia related service.


Using process explorer ive noticed one of the csrss.exe uses, and is the only process to use my gpu when idle. I am using aero, but dwm.exe does not use anything. (Unless dwm uses csrss or something).


Idle, it generally uses less than 0.50pc of my gpu. When I start interacting with the windows aero environment, it can spike to 10-20% or just consistently stay at 15ish per cent untill I stop, for example making all windows transparent etc.


Any idea if this is normal?

 

[RaDiKaL_]

Post your full PC specs, an old video card struggles with Aero function (which is controlled by csrss.exe) but a decent one and upwards should have no problems at all.

Also I'm not sure if you should have 2x csrss.exe running, but it's been a long time since I've used an Nvidia card so maybe that's normal with nvidia drivers, look from where each csrss.exe is being executed, both should be from c:\Windows\System32\csrss.exe (regardless of 32 or 64bit windows version).

 

[Keyes]

The system is in no way struggling (no lag or slowdown noticeable, only the graphs shown by process explorer are to tell)


I5 3570k
8gb ddr3
gtx 970 4gb

When I play a game like battlfield 4, gpu utilisation with aero on is no bother at all. I will add that this csrss.exe process is often using cdd.dll which I believe ia aero related.


My only question is that is thia normal activity?

 

[RaDiKaL_]

No it's not normal, here with my old HD 4850 my csrss.exe doesn't go above 0.04% CPU usage, that's why intrigues me the fact that you have 2x csrss.exe running, hopefully someone who owns a Nvidia card might help you clarify if it really loads up 2 instances of said file or only one.

 

[Keyes]

When I left my system idle, I found it was pretty much at 0-0.03%. Not cpu, but gpu usage.I found this information

Under DWM, GDI calls are redirected to use the Canonical Display Driver (cdd.dll), a software renderer.
So perhaps it's something in csrss.exe actually redirecting calls to cdd.dll. Confirmed further by going back to the first Wikipedia article:
instead of issuing a system call, the Win32 libraries (kernel32.dll, user32.dll, gdi32.dll) send an inter-process call to the CSRSS process which does most of the actual work without compromising the kernel.
So application calls to gdi32.dll (which would be anything that renders any Windows GUI component like buttons, scrollbars, text, etc.) end up making their way to csrss.exe via IPC, which csrss.exe redirects to cdd.dll.

 

[RaDiKaL_]

Interesting info, well I guess that if it doesn't slow down your pc nor anything like that then its ok.

 

[Keyes]

I made a post on superuser, maybe you could check it out (its in a lot more detail)

http://superuser.com/questions/858140/explantion-for-csrss-exe-using-the-gpu-windows-7-x64

 

[Keyes]

This image also shows, not mine, but someone elses usage.

http://superuser.com/questions/585532/how-can-i-identify-which-processes-are-using-the-gpu