Unknown Graphics Error.

iniaes

Reputable
May 31, 2014
8
0
4,510
The problem machine is a Dell XPS17 with the 3D vision Nvidia 555M GPU (3GB DDR5 variant).

I have been suffering from in a consistent type of intermittent graphical fault across several games which causes:

Occasional GPU driver failure and restarts; game still plays. (Occurs in Space Engineers)
CTD; Game 'stops responding' (Common across all of my Assassins Creed games)
Persistent graphical glitches / rendering artifacts.(KSP)

The artifacts are a common symptoms to all of these faults but they cause differing degrees of disruption to my game play:

30964r8.png


These strange square glitches occur in varying numbers and don't seem to have consistent placing. I believe they MAY be related to textures with an alpha layer, as when I maneuver the camera over cast shadows, the glitch disappear, but 'behind' the glitch is no shadow.

With regards to the AC games, the splash screens load up fine, and the intro sequence for AC:1, but as soon as the game goes to open the main menu they CTD.

I have tried removing and reinstalling my Nvidia Software and drivers, reverting GPU drivers, and direct x diagnosis. Starting to pull my hair out so any idea or help would be appreciated.

If you need more information, please let me know.


Glitches are present over land:
23w2nq1.png


But if I pan the camera and move them into the sky, they disappear::edit:: in game these glitches dissapear, but in these screenshots they are changed, but still visible::
2u8kxaw.png


The glitches reappear in their previous position on returning the view to the land.

The nature of the glitch in the AC:Brotherhood menu screen:
2lutoio.jpg
 

iniaes

Reputable
May 31, 2014
8
0
4,510
I have had the laptop away to the OEM for maintenance recently due to a PSU fault. And I air-dust it regularly. I did ask for the cooling paste t be re-done though, could it be that they borked the job?

Is there any diagnostic software i can use? I have stripped down the laptop before so I have no qualms about re-redoing the cooling paste if I have to.
 

bignastyid

Titan
Moderator
It's possible. The vram will usually use cooling pads rather than thermal compound. Since you are comfortable tearing down the system cheacking the pads and re-doing the thermal compound may help. Usually there isn't temperature sensors on the vram just the GPU. But GPU-Z will show you the GPU temp and vram temp if available.
 

iniaes

Reputable
May 31, 2014
8
0
4,510
At idle, with power saver mode on, the GPU is @ 44 degC, with other device temperatures ranging from 34-50 degC. Fan throttled down to it's lowest settings automatically. (Other device temperatures gathered via Speccy).

On starting KSP temp rises to 50 at the loading screen on ~5% load. After the loading screen GPU temp rises to 54/55 on a consistent 78% load, with no throttling up of the cooling fan. MOBO and CPU temps are now up at 55.

 

iniaes

Reputable
May 31, 2014
8
0
4,510
Right, been stress testing the system using OCTT, it runs some sort of furmark-esque bench, uses all the GPU ram and maxes out the GPU and CPU usage, temp never goes over ~76 degrees in an hour on the CPU and maxes at ~80 on the CPU (which was a little terrifying). But the graphical glitches do not appear, and there is no CTD or BSOD.
 

iniaes

Reputable
May 31, 2014
8
0
4,510
Right, been using GPU Shark to monitor OpenGL RAM use, whenever the GPU goes over ~300MB of Ram the artifacts start showing. Does the diagnosis still stand?
 

iniaes

Reputable
May 31, 2014
8
0
4,510
Well, done my teardown, and thoroughly enjoyed it, looks like Dell done a nice job with the heat management system to be honest, none-the-less I replaced the heat pads and tidied up the thermal paste on the GPU and CPU, a,d for good measure added thermal tape to the VRAM chips just to guarantee connection with the heat conductor.

<a href='http://postimg.org/image/dctesl8h9/' target='_blank'><img src='http://s30.postimg.org/dctesl8h9/artifacts_at_500megs_VRAM.jpg' border='0' alt="artifacts at 500megs VRAM" /></a>

But the artifacts still turn up. What is more annoying is I have found a benchmark which stresses the RAM as well as the GPU; MSI Kombustor. With the GPU at 99%, VRAM usage at 72-77%, and GPU steady at 71-72 the benchmark screen, full or windowed, has none of the artifacts showing, no matter how I stretch or skew it, and regardless of the resolution I run the benchmark at!

<a href='http://postimg.org/image/oe6flvm9j/full/' target='_blank'><img src='http://s7.postimg.org/gy7602ykb/bootmark.png' border='0' alt="bootmark" /></a><br /><a target='_blank' href='http://postimage.org/'>image url</a><br /><br />