Artifacts with new Gcard/Ati Overdrive?

[Rick Martel]

installed a Ati HIS 4850 last week, been running games fine on it.

but then i installed Ati overdrive overclocking software and did an "Auto Tune" to speed up the Gpu Clock and Memory Clock.

it determined (after 10 minutes of GPU testing) that it would run stable at the following speeds.

700/700 GPU
1100/1200 Memory

@ 69Celcius Max load.

started up some games and it was fine, shut down the PC, and when i turned it on today there are artifacts blinking across the screen all over the place. so i reset the Gcard settings back to default and disabled Ati Overdrive but now im getting low FPS (damaged card?) but the artifacts are gone. No other components are overclocked.

why did Ati Overdrive cause artifacts if it automatically set the GPU/Memory clocks and determine it "Safe"?

 

[Mr Paul]

Because it generally overdoes the memory clock.

 

[Rick Martel]

Because it generally overdoes the memory clock.

so artifacts can occur even if the card hasnt passed its temperature threshold based on memory speed alone?

 

[Greebo]

it doesn't do a very good stress test.

On my 4870 it reckons 875/1100 is fine. I can tell you within 5 seconds of ATI tool i have yellow dots

 

[Xiler]

auto tune doesnt do a good job shouldnt even be there in my opinion.

u will need to do it manually

 

[=VTA=MANFACE]

I've gone back to stock settings.

 

[Durzel]

ATI CCC AutoTune is useless, it thinks my 4870X2 can do 890/990 or thereabouts when in reality trying to play anything at those clocks is like looking down one of those kaleidoscope tubes.

And yes, hardware can show artifacts even if its not overheating. Could be not enough voltage or simply that it cannot run at those speeds.