Low Score with Luxmark 2 / GTX285 & 9500GT

[tilllt]

Hey People,

 

i have a dual graphic card setup on my EP45-UD3P. I am running a GTX285 and a 9500GT. Both work fine, i hope with the CUDA driver update now system crashes are gone.

 

Out of curiosity i was running the Luxmark 2 OpenCL Benchmark with disappointing results. The Complex Scene gave me a result of 127... If you search the result database for GPU-Only results running the GTX285, the submitted results range from 148 to 2636 (!) ... so what exactly am i doing wrong here?

 

ciao,

t.

[mitch_de]

First : Be sure , if you compare the Luxmark results (in the results db OR in the Luxmark 2.0 Thread here) that you compare same scene!

The complex scene gives much less points than the other 2 scenes.

Also look at the Info viewed about the GPUs used on the right side and the log view below the rendered window. Then you will see if both, or only one and whch one is benched. You can select the gpus which are used if you go into pause mode (menue), select /deselect the gpus right side and run in selected gpus only.

 

It can be in case of using 2 gpus with very much speed diff (9500GT is less than 1/5 in speed of GTX 285!!), that the slow gpu has NEGATIVE effect on the overall speed - at least if you have no highend CPU also. i7 or highend Quad CD cpu is really needed to get 2+ gpus woring with Luxmark 2.0.

Thats because the low speed 9500GT also uses the CPU (1/2) for doing the OpenCL overhead on the cpu which always happens.

GPU only doesnt mean the cpu is much idle. The more GPUs (and the faster one gpu is) the more the cpu effects also the overall speed - at least for such very complex OPenCL code like Luxmark.

Only 2 similar gpus (in speed) will get really higher results - AND only then significant , if your cpu is also an fast 2.8+ GHz quad cpu. C2D, downt matter how much GHz cant handle more than 1 gpu good at so complex OPenCL computing.