Memory problem?

[MadCat]

I find this really strange: I have a 16mb SGRAM OEM G400, and in all other games the thing runs great, no visual glitches. I can overclock the hell out of it too...the memory can take 190mhz before the games start messing up. But in Q3A, even at default clock speed, im getting white dots along the edges of polygons. Is this a lack of 32mb memory problem, or a glitch with the TurboGL, or do I just have a bad board? I hesitate to blame it on a lack of memory, as my old 16mb TNT didnt have this problem with the exact same settings.

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[Wombat]

Have you eliminated heat as a possibility? That's what would happen when my G200 would get too hot (since it was being 30% overclocked). Make sure it's cool in there.

[bogie]

Did you try to change the resolution to 1024X768?

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bogie
working rig:Epox KP6-BS, dual PPGA Celeron 366 o/c at 550, 256SDRAM/PC100, FlashPoint Wide SCSI controller, 9.1GB Seagate Cheetah,
5.1GB Quantum FireBall EX, Creative 5240-E1 DVD-ROM, SB-Live Value, Genius GF100TX NIC,
G400 DH-32MB/170MHz core, 190MHz memory

[MadCat]

Cooling: I have a case fan located at the bottom front blowing cool air inward over the expansion cards. I also have a 40mm fan blowing air directly across the G400's heat sink.

I have tried the card at both default clock speed, and resolutions ranging from 640x480 to 1280x1024. The dots become less noticeable at higher resolution, but thats only because theyre the exact same dots, just smaller due to the higher res. The dots only appear along the edges of polygons, and they will dissappear or new ones will appear as your POV changes. This happens with any color depth, both 16 and 24-bit Z-buffer.

As for clock speed, thats not a factor. I can set the memory at the default 168mhz, then up it 15mhz, and the same proliferation of white pixels remains. Overclocking seems not to affect it. I personally CAN tell you that this memory can take 195mhz...thats when Quake3A started showing texture bleeding and artifacts.

You know, the more I think about it, the more I think this might be a depth buffer precision problem. Slight inaccuracies along the borders of polygons could cause this. Ill try uninstalling the turboGL, and see how things work.

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[MadCat]

Alright, ive comfirmed it, the TurboGl is the cause. Ill bet Matrox skimped on some feature or something to maximize speed. In any case, the speed increase I get with the turboGL is still too much to just dump it over a fe white dots...hope they fix it. THX for the help everyone.

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