multi GPU slower then single GPU ?

[radiance]

can you try with 197.45 whql ?
(you can download it from the main nvidia website)

Radiance

[ribrahomedesign]

ok ,will do that

[Amplitude]

have you tried with another scene also to be sure it's not scene dependent ?

[radiance]

have you tried with another scene also to be sure it's not scene dependent ?

I'd like to suggest also trying to render at high res, something like 2048x1024 or something.
see if that has any impact.

Radiance

[ribrahomedesign]

i will try with a diffrent scene ,and higher res, at the moment i have to restore my machine ,because the
download of the latest driver 197.45 frezzed my computer
let you know how i get on with it.
thank you very much for the support
regards
Rico

[ribrahomedesign]

ok here i am again .
i went back to the older driver 197.13 and rendered a outside scene with pathtracing
here the results
1 GPU : 1,12 Megas. per sec. 1.42 FPS
2 GPUs: 1.94 Megas.per sec , 2.46 FPS
do you think thats about the wright performance ?

can pathtracing slow down multyGPU that much ?

thanks for support
Rico

[radiance]

ok here i am again .
i went back to the older driver 197.13 and rendered a outside scene with pathtracing
here the results
1 GPU : 1,12 Megas. per sec. 1.42 FPS
2 GPUs: 1.94 Megas.per sec , 2.46 FPS
do you think thats about the wright performance ?

can pathtracing slow down multyGPU that much ?

thanks for support
Rico

that sounds about right. non-GTX400 series cards get about 1.6 to 1.7 with beta 2.2
it should increase at higher resolutions.

so the 197.13 driver solved the issue ?

Radiance

[ribrahomedesign]

i dont think it was driver related ,it was scene related , i will try with the 197,45 driver again later,
but i am not sure if this driver has a stability issue or not, it didnt work on my system .
thanks anyway.
Rico

[Amplitude]

Looking into it myself I suffer from the same performance hit as you !
Even on the trench benchmark scene. That's the most strange thing as I've run this scene last week without a glitch and get normal performance out of my two cards (around 11min for the bench).
Also monitoring the GPU load, they don't go any higher than 60% each. (in fact fluctuating rapidly between 45% and 60%). that's insane!?

edit: after a reboot the performance is back to normal.