6800nu AGP hesitation issue

[Flipped Gazelle]

I recently got a Leadtek 6800NU AGP 128mb vid card, and have run into a curious issue. The default clocks are 325/700, and they easily overclock up to 400/900. I have successfully unlocked the 4 locked pipes and the vertex shader. However, under DirectX apps (Aquamark, 3DMark 03 & 05), there is a periodic hesitation during gameplay about every 10 seconds or so. There is no hesitation with OpenGL apps (Doom3, Quake4). When I drop the core speed down from 400 to 375, the hesitation problem goes away. Any thoughts on why this happens?

My system:
AMD Athlon 64 DTR 3000+ (1.8ghz@2.5)
2x512 DDR400

 

[BlacKJesuS]

prob means yer overclocking too far

 

[Flipped Gazelle]

Originally posted by: BlacKJesuS
prob means yer overclocking too far

Well, yeah, I would think so. What makes the issue so curious is that the hesitation problem only exhibits in DirectX - not OpenGL.

 

[CKXP]

Well, yeah, I would think so. What makes the issue so curious is that the hesitation problem only exhibits in DirectX - not OpenGL.

probaly because Nvidia excels in OpenGL games, by way the nice clocks on 6800nu(400/900) mine will only do 390/875 stable.

edit: also is fastwrites on?

 

[Hyperlite]

400 core for stock core voltage is pushing it. its probably throttling.

 

[Flipped Gazelle]

I think Hyperlite's correct... it does seem to be a GPU throttling issue...

I used Rivatuner to diable the GPU throttling, then cranked up the core to 400mhz. Sure enough, after running Aquamark3 for about 30 seconds, I started seeing serious artifacts. But not in Doom3. DirectX appears to put more of a strain on the card. Back down to 375, I guess.

Thanks to all who responded!

 

[Nextman916]

You back down to 380