I recently had a discussion with the Gentoo Linux maintainer of the nvidia-drivers package [1].
The driver download page for version 340.46 [2], doesn’t list support for the Tesla K40c. On the other hand the README for 340.46 [3] 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.
[1] https://bugs.gentoo.org/show_bug.cgi?id=526632
[2] http://www.nvidia.com/Download/driverResults.aspx/78469/en-us
[3] http://us.download.nvidia.com/XFree86/Linux-x86_64/340.46/README/supportedchips.html