Geforce 6600GT AGP problems? Try this...

[Mutley]

...Especially if you have a motherboard with an SiS chipset (or VIA)...

Over the past couple of weeks, I posted a few threads on problems I was having with my new XFX GeForce 6600GT AGP graphics card. Here they are:

6600GT and Battlefield 2 problems
Possible problem with display timings...?
Real problems with XFX GeForce 6600GT AGP

Anyways, I've spent a fair amount of time figuring out whats going on, and how to fix the problem. So I thought I'd post my findings here, in case it might help anybody.

In summary, the problem is that on newer games, such as Battlefield 2, various nasty things happen (depending on various BIOS and other settings). Typically, you get one or all of the following:

o Wierd texture corruption, like some hippie artist has been in to the game and repainted everything. You get nice glowing leaves of bright colours on trees, chimney stacks appear in a fashionable and fetching blue camouflage and so on.

o Polygon wierdness - odd lines stretching across the screen. After a while, you can't see anything because more and more polys get stretched to infinity.

o Game lock up. The game freezes, and after a few moments the screen goes blank, and the VDU goes into stand by. The pc is still running however. This needs a hard reset.

o BSOD, with an error such as
"problem with nv4_disp.dll" or
"Page fault in nonpaged area"

These problems don't tend to occur immediately, but after a few minutes play. Another curious symptom is that you may be able to go through benchmarks such as AquaMark3 and 3Dmark05 with no problem (at least to begin with).

With these problems, you would think the problem would be:

o Bad or inadequate PSU
o Graphics card is overheating (maybe cos its OCd)
o Bad ForceWare drivers
o Old BIOS or AGP drivers
o Faulty card.

Here are two useful threads on other forums which provide some insight to these issues, and others might find helpful.

http://forums.nvidia.com/index.php?showtopic=1029
http://forums.nvidia.com/index.php?showtopic=1159&st=0

What I found can be added to this.

I keep my machine pretty clean and up to date. The only thing that was out of date were the AGP GART drivers, which I duly updated. This didn't help.

I tried switching on and off AGP Fast Writes in the BIOS. This made little difference.

I tried down rev'ing to an earlier ForceWare driver (77.77) from the 81.85 I was using.
This helped a little. one problem I had with VDU sync issues went away. I believe this is due to 81.85 being crap.

I installed RivaTuner (a most excellent tool by the way), and switched on motherboard compatibility mode, which is specific to SiS, VIA, nForce and a few other type boards. Now, this combined with switching Fast Writes on did seem to work, but I still experienced odd screen flashes.

I then switched off Write Combining. And BINGO. No more problems. I noticed this switch while reading tweakguides guide to ForceWare tuning. You get to it by right clicking on the Windows desktop, clicking Settings, Advanced (think it is), then clicking the Troubleshooting tab. Its on by default.

If you look up context-sensitive help on this, you are told this can improve performance, but can cause some texture problems. SO WHY THE HELL IS IT ON BY DEFAULT!!?????

I went back and retested everything I had done - switch fast writes on and off, turning off RivaTuner's motherboard compatibility mode, and it still all works. Not only that, but with Write Combining switched off I appear to get higher benchmark scores.

I've tested a bunch of games - BF2, HL2, DOD:S, Far Cry, NFS:U2, GTA:VC. All work, very well. BF2 stutters a little but I would expect that with 1Gb RAM, and 128Mb graphics card.

i'm still using the 77.77 Forceware drivers cos they work. Not tested the latest ones yet.

So, either before you try anything else, or after you have, try switching off "Enable Write Combining"! Check here for the Tweakguide.

My PSU is an Enermax 350W job. It provides a stable voltage on the 12V rail, giving 17amps. This PSU runs the graphics card, 3 92mm fans and 2 cd drives. I've read posts that say you should have a 450W PSU with at least 20amps on the 12v rail. This is not true unless your PSU is crap. Lesson? DONT GET A CRAPPY CHEAP NO-NAME PSU.

One other thing: Make sure your BIOS and system drivers are up to date, and when you install new drivers, make sure you really clean out the old crap using drive cleaner and a registry cleaner (there are links to these in the above nVidia forum links).

I hope this is of use to someone - I'm certainly happy now!

Mut.

[sawyen]

good stuff, nice post mut..

[GFiSH]

Thanx for that, I've for one of those cards, if I'm having problems I now know where to come.

[Mutley]

Originally Posted by sawyen

good stuff, nice post mut..

Thanks! Frustrating exersise, but worth it in the end...

[abacad]

Same card, same Chipset, same problems

Another thing that might be useful is, when uninstalling/cleaning out the old drivers I also removed all/any codec packs. This allowed me to successfully update to the latest Nvidia drivers.

An easy way to test if the drivers are installed properly is to try and open a video file. I know it sounds obvious but a faulty driver install will still appear to be working ok until you try to play games or watch video files

[Mutley]

Thanks for that abacad. Anybody with useful ideas should drop em in here, and we can have one almighty thread with lots of solutions!

[robbie43]

Yes, great Idea. I spoke to Mutley earlier and i think Im the first in which his same problem solved mine in an identical fashion!!! yay. thanks mutley

Disable write combining and all Artifacting dissapears. Also im using the very latest 81.85 drivers without problems unless I overclock the card to borderless limits in which i then get small artifacts....obviously enough.

serious though -> "THE ONLY POST ON THE ENTIRE INTERNET THAT WILL SOLVE THIS ISSUE" lol Cheers all.

[YonKat]

Hi, I just have to say THANKS

I have a Geforce 7800 GT and I was having the problem where the graphics were stretching in some games.I looked for a solution for a long time, and I was starting to think that it was something wrong with the card. But I disabled "write combining" and now everything works good!

[Mutley]

Cool! Another satisfied customer.
Glad to have helped.

Mut.

[squishypickle]

I just suddenly started experiencing all of the above problems, except for the funky colored textures. I have a Chaintech 6600gt agp, and a Nforce2 motherboard. I admit, it happened immediately after I tried to overclock it a little bit. I read others who bumped up core/memory speeds by 100mhz or more successfully on stock cooling, so I tried a fraction of that and ran into problems. The first time, it worked fine, but when I tried it recently, the stretched polygons and crashing remain even at the stock speeds. Write combining off helps somewhat, as well as using the new beta MSI drivers, but only delays the problem. I don't think briefly overclocking should have broken it. Am I screwed?

[Mutley]

Were you able to measure the temp on the GPU core when you OC'd it? Could be that the cooler you have is not very good, and the GPU is very sensitive to OC and/or heat changes.

[reyerd]

I have followed the guide, and then I managed to start a game witout the reboot/locking.

But the problem now is all is funktional, but many artifacts in the game, and the menu looks like bad shi*. Many rainbow colours!

could this result in a to little psu? my chieftech is 360w and 17a on the 12v

[Syfer]

Excellent! I was experiencing artifacts on a few games on my sons PC. Switched off write combining & all is well!

Thanks.

[EJ70]

Mutley, thank you so very much for solving this issue and sharing the information. I've been having similar problems with my 7600 GS AGP card from EVGA, not the rainbow colours, but the artifacts (long polygon spikes) appearing after several minutes of playing, for instance in F.E.A.R. I too was advised to install a new PSU, but it made no difference. The support desk at EVGA just stopped answering my questions, probably because they had no idea where the problem lies. So after months of frustration and finding no useful help on the internet I was starting to think about the problem of how to get my money back. I tried one last time on the internet and now found exploding-planet.com/weblog.php?count=1&id=233 which has a copy of your solution linked to the 7600 chipset. Since I had already placed my old card back in the computer, I re-installed the 7600, unchecked combined writing, and everything works fine now. Un-be-lie-va-ble...

BTW I also have the SiS motherboard, and previously had an ATI Radeon 9200. I haven't check it, but I wonder now if the combined writing option is switched on when installing ATI graphics drivers. Or is that unlikely?

I would further like to suggest that you post a message, mentioning all nvidia AGP card numbers (if there are more than the 6600 and 7600), since it is now likely they all have this problem. It will allow owners of those cards to find this very useful thread through search engines more easily.

Thanks!

[Mutley]

I have to say it is very gratifying to get positive feedback on this post, and to see that this has really helped a number of people - makes the pain worthwhile!

As for whether or not all AGP GeForce cards are affected, I don't know. I believe the problem is related to certain nvidia chipsets and SiS chipsets. I have a 6800GT currently, and that has different issues...

Mut.

[yogi bär]

hi mutley,
i just joined, to say, i love you.
whatever......
just tried for about 3 weeks, to get gothic 3 running. with your help its done.

thank you so much. greetings from germany.