CUDA speeds up after starting firefox with flash-application

My CUDA program behaves kind of strange: if I start the program without doing anything on the pc before it takes up to 150 ms longer (total runtime 4 sec) than when I start firefox with a flash site running.

Is there anybody who made the same experience? Or what am I doing wrong?


  • CUDA 2.3
  • Intel Q9600 Processor (3.0 GHz quad core)
  • GeForce GTX 295
  • Windows XP 32 bit
  • 4GB system RAM

That’s the dynamic throttling of the card… it lowers the clock rates down when the gpu is idle. It takes about a second to spool up to full speed, then it stays there for a while afterwards and then slowly drifts back to idle.

You can turn off this behavior in the driver (in Linux it’s easy, it’s a control panel button in nvidia-seting , in Windows it’s also in the Nvidia settings, called “PowerMiser”).

The flash app is obviously using the GPU and that means it’s already spooled up.

Thank you!

Disabling Powermizer does not solve the problem. The GPU clock is at 576MHz in all cases: powermizer on/off, starting/not starting firefox and also the time differences stay the same.
I get the GPU cloks from GPU-Z.
I’m using 196.21 drivers.

I’m using both GPUs in my program. Is there anything I have to do at initialization time like init 3dperformance or sth. like that? Any guess?