need titan x driver

how can i get titan x driver for ubuntu 16.04 ? i can not find on nvidia web ,there just only titan V

Use the current driver from ubuntu’s graphics ppa:
https://launchpad.net/~graphics-drivers/+archive/ubuntu/ppa

no, do not use https://launchpad.net/~graphics-drivers/+archive/ubuntu/ppa, as nvidia doesn’t support and maintain that repository.
Instead use https://developer.nvidia.com/cuda-zone