Author Topic: M3N78-EM Video Issues  (Read 2218 times)


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M3N78-EM Video Issues
« on: October 08, 2009, 04:20:55 pm »
Hardware setup:

M3N78-EM Motherboard w/ Brisbane Processor (onboard nvidia 8300)
1080p 60Hz Panasonic Plasma TV (TH-50PF11UK)

I've been having trouble with very sluggish UI2 (no alpha blending) and very bad tearing in 810 with my installation on this hardware. OpenGL performance seems to be all around terrible. I have tried many different driver versions from 177 to 185.

I believe the issue is not caused by LinuxMCE. I am posting here regardless because I know there are a number of users who have the same motherboard and I am appealing to those people for help.

Why do I think the issue is independent of Linuxmce?

I decided to reinstall Kubuntu 810 and evaluate video performance BEFORE installing linuxmce.

Independant of nvidia driver version, VGA, DVI, or HDMI port: Glxgears run in a maximized window with VSync turned off is giving 45fps, stutters and tears horribly. Turning vsync on, the framerate drops to below 25 and the test looks even worse. I did this same test a while ago with an 8500GT PCIE installed on the same mobo and got framerates closer to 600 to 700 with no VSync. Everything worked wonderfully with this PCIE card.

Questions for M3N78-EM users who have working setups:

Below is the last few lines from "cat /proc/interrupts"

Code: [Select]
16:         56      13942   IO-APIC-fasteoi   eth1
 17:          0          2   IO-APIC-fasteoi   ohci1394
 20:        232     377198   IO-APIC-fasteoi   ehci_hcd:usb4, nvidia
 21:          0        309   IO-APIC-fasteoi   ehci_hcd:usb3, HDA Intel
 22:          1        272   IO-APIC-fasteoi   ohci_hcd:usb2
 23:          3       8813   IO-APIC-fasteoi   ohci_hcd:usb1
219:       1572     633093   PCI-MSI-edge      eth0
220:         87      67450   PCI-MSI-edge      ahci

Does this look different from yours? Has anyone managed to get nvidia on its own interrupt through some bios settings?

How does your glxgears performance compare to mine?

Could video performance be compromised if the card is not running at a precisely standard resolution / modeline timing?

I found the following in my Xorg.0.log:

Code: [Select]
(==) NVIDIA(0): No modes were requested; the default mode "nvidia-auto-select"
(==) NVIDIA(0):     will be used as the requested mode.
(==) NVIDIA(0):
(II) NVIDIA(0): Validated modes:
(II) NVIDIA(0):     "nvidia-auto-select"
(II) NVIDIA(0): Virtual screen size determined to be 1920 x 1080

It seems the plasma TV is not communicating EDID information properly as I recall usually seeing mode validation performed in this section of the log. Could this be related somehow?

Anyone have any idea what could be wrong with my setup?

Thanks in advance.

EDIT: Fixed CPU type
« Last Edit: October 08, 2009, 04:27:45 pm by davegravy »


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Re: M3N78-EM Video Issues
« Reply #1 on: October 08, 2009, 04:56:09 pm »
For quite some time now I have been using the same board on a diskless MD without any problem.  I don't know which processor you have but I have the AMD 7750 Black Dual-Core CPU on mine and I don't have any problems with video.  I am presently now using the Basic Titanium Menus, only because there is still a bug in the UI2's ability to see multiple floorplans.  When I was using the UI2 with or without Alpha-Blending, I had no problems whatsoever.  

I am also using the HDMI connector without audio, and I have not not ever worried about that because I send the audio straight to my surround receiver by way of the ASUS's optical Toslink fiber output.

I'm also using the nVidia, 180.xx driver, stock from the repository, with no lag or tearing.

Check what processor you have on the MB and maybe another gig of memory may help.  Oh yes, I have 4 gig of memory, an overkill, 2 gig should do it OK.

Best Regards,


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Re: M3N78-EM Video Issues
« Reply #2 on: October 08, 2009, 05:21:24 pm »
Thanks Charles.

From my reading on nvnews forums, some IGPs on asus boards are picky about BIOS versions (with older BIOS versions being better!)

Can I ask other M3N78-EM owners what BIOS versions are you running.

Thanks very much.