# NVidia problems....Interference patterns

## matthew

Hi, 

  I have a GeFroce4 440MX, and a SOLTEK SL-85DRV4 C running Gentoo Linux, and whilst for the first hour or so the PC is fine, after that a interference pattern appears on the monitor, and then some time after that the system locks up. The system is NOT overclocked in any way,shape or form. I've check for heat etc, and the system stays quite cool, most of the time the case is off though (the problem appears indepenant of the case). So 

far I have tried (no difference unless stated):

Swapping monitors

Changing refresh rates (makes the interference pattern less)

Moving speakers and subwoofer

Putting monitor on different power circuit.

Changing OS -- Problem seemed to disappearing in Win2K (but I wasn't there for long)

Changing card - NVidia GeForce2 440 MX - Problem went away

Tweaking AGP driving force to DA (as per Mobo manual), and EE as per Nvidia instructions

Recompiling kernel, 2.4.20,2.4.19-gentoo-rc10, 2.5.60-something

Any ideas... My thoughts point at the video hardware (I should try staying in Windows longer to see if it does appear first though.....)

Cheers

Matthew

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## Malakin

Try using nvclock to underclock your video card and see if it goes away.

"emerge nvclock"

instructions on using it here: 

http://www.evil3d.net/products/nvclock/?section=Installation&page=3.php3

If emerge gives you errors just download their source and compile it yourself. (emerge didn't work for me)Last edited by Malakin on Wed Feb 19, 2003 8:00 pm; edited 1 time in total

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## AlterEgo

Which version of the nvidia drivers are you using? The 4191 is known to sometimes cause lockups randomly (search the forum!). It can be stopped by disabling 2D accelleration in /etc/X11/XF86Config <example>:

[Section "Device"

    Identifier  "GeForce "

     Driver      "nvidia"

 #  Option "RenderAccel" "1"

EndSectionquote]

The interference problem is really strange: lowering vertical refresh rates might help.

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## matthew

OK, I've tried both the 4191 drivers, and the ones previous to that (at work at the mo so can't remeber the version number ), the problem appeared with both....

With regards to nvclock, should I underclock the core or memory clock?

I have searched the forum, and other things tried include playing with the NvAGP setting (currently 1) - Made no difference

I tried to disable RenderAccel but I seem to remember using a different syntax, I think it was Option "NoRenderAccel" "true" or something like that.... Will know more when I get home.

I've also tried using the codas modeline generator with 350 as the dotclock of the card, and the correct settings for the monitors I've been using, and still no joy. I'm pretty sure it's not environmental.

This evening I'll try the RenderAccel thing, and W2k for a length of time and post more later..

Thanks guys...

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## AlterEgo

Please note:

Option "RenderAccel" "1"  is nvidia 4191-syntax

Option   "NoRenderAccel"  is nvidia 3123 and older-syntax

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## Malakin

 *Quote:*   

> With regards to nvclock, should I underclock the core or memory clock?

 I'd do both, if it fixes it then try just one at a time until you figure out what's causing the problem.

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## matthew

OK, I've tried adding 

Option "RenderAccel" "1" to XF86Config-4 as it wasn't there, and still no joy ( the interference wasn't there though, but it did crash pretty quickly..

Will now try underclocking the card..

I booted back into Win2k for a good few hours and played a few games to work out the processor and card, and apart from a instance where the screen went black and then carried on after a second or so every thing was fine.

Now back in linux and within a few minutes the problem is back!.

Tried under clocking, went right down to memory=200Mhz and core=100Mhz (below that caused X to become unusable), still now joy....

I've removed the energy efficient bulbs from the room just in case they were causing the flickering...long shot I know.

Still no joy..

Matthew

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## BlackBart

I had that problem, when I upgraded xfree to the latest unstable version it went away. This was probably because my other card stopped working though...

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## matthew

Emerged the latest XFree (ACCEPT_KEYWORDS="~x86") and still the interference and instability. I might go back to the 3123 drivers and test the stability with them.   

Does anyone know of a way of getting a modeline that represents a screen setting in Windows?

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## Malakin

Did you try disabling AGP?

Option NvAGP = "0" in your /etc/X11/XF86Config files just under driver "nvidia".

The Nvidia docs used to say to use an agp drive strength of EA, now they say somewhere in the range of EA-EE, I've always used EA though.

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## matthew

Still with the 4191 drivers and now NvAGP set to "0" the interference pattern appeared pretty quickly (not straight away though).

Have changed AGP driving force to EA and it's still not having any difference.

Also have removed every PCI card I could, and it's still there. Even if I drop the screen down to 800x600@80Hz I get the pattern.  It's driving me mad..  :Razz: 

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## BlackBart

 *matthew wrote:*   

> Emerged the latest XFree (ACCEPT_KEYWORDS="~x86") and still the interference and instability. I might go back to the 3123 drivers and test the stability with them.   
> 
> Does anyone know of a way of getting a modeline that represents a screen setting in Windows?

 

dang, that means that it probably won't work for me either once they get a working s3 driver

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## matthew

OK, now trying the 3123 drivers with the follow XF86Config-4

```

Section "Device"

   Option "NvAGP" "0"

   Identifier  "Card0"

   Driver      "nvidia"

   VendorName  "NVidia"

   BoardName   "0x0170"

   BusID       "PCI:1:0:0"

EndSection

```

So far it hasn't crashed on me, touch wood.

I will now try all the things suggested such as the "NoRenderAccel" with these drivers.

Also I've disabled dri,record, and xtrap as I found reference to doing this in another post today.

Thanks

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## matthew

OK, So it's still not stable, no changes since last post, but the damn thing just crashed on me again. The screen exhibits the same effect as when I underclocked it too far.

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## matthew

Thanks for everyone's help, Last night I had had enough and decided to go back to the GeForce2, so I swapped the card with my wifes, and after about an hour on WinXP and a different PC the interefence came back on the GF4, it was very very slight, but it was there......So the card is going back to the shop tomorrow. Will post the results with the new card when I get it back.

Cheers 

matthew

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## matthew

Well, I've been running now for a few days with the new card, and no interference pattern yet (no crashes either (but I'm still using 3123 drivers)).

Seems like it was hardware after all. Strange that it only showed on WinXP and Linux though (not Win2K).

Thanks again.

Matthew

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