I recently had a discussion with the Gentoo Linux maintainer of the nvidia-drivers package .
The driver download page for version 340.46 , doesn’t list support for the Tesla K40c. On the other hand the README for 340.46  says the K40c is supported. So the question is, why this information is not consistent. nvidia-healtmon and nvidia-smi work fine with version 340.46 and the examples seem to work correctly.
A statement if the K40c is supported or not would be highly appreciated.