Power consumption/management Power-downwhen inactive

I have a 9800GTX, gotten for the sole purpose of being a hobby computing device (compsci student). Now, I can get video out from it, or from another card (builtin on the mobo or other plugin card), if necessary for the following to work:

When the card isn’t busy doing calculations, I would like for it to use as little power as possible, to keep my room moderately cool. Is there a way (nvclock, CUDA-API calls, binary-nvidia driver options, other) to tell the card to go into the most sleeplike state possible?

I wonder both for the cases of it being used as a dumb framebuffer (X-terminal with a couple of xterms), and in the case where there’s no display at all attached to the card.

Thanks in advance,
Henrik

It already clocks down quite a bit when not being used for 3D or CUDA apps. I doubt you’ll be able to do any better than that.