And do you see the 3 performance levels of Powermizer with nvidia-settings?
Can you use the 1.7GHz mode? i.e. what happens when you run glxgears and ...
nvidia-settings -q all | grep GPUCurrentClockFreqs
In my GT240/GDDR5, it always reports...
Attribute 'GPUCurrentClockFreqs' (home:0.0): 405,324.
...when in fact, under Windows, the card runs at "550,1700", i.e. with a memory bandwidth 5.25 times faster!
It appears that with the current drivers (195.30 and 190.53), performace level 3 is disabled in GT240/GDDR5, and the result is abysmal performance in almost everything: glxgears scores around 4000 fps (!), and CUDA code runs between 10% - 30% of the corresponding speed under Windows (depending on how much the algorithm depends on memory accesses).
This is basically making the card slower than 30$ cheap NVIDIA models...
Please fix this, NVIDIA.