If you want to easily overclock your asus 5950u card, then you either need to, use a proprietary ASUS overclocking tool, or, flash your card with any other manufacturers bios.
ASUS bioses are not made in accordance with Nvidia design spec. For some reason only known to asus, they decided to store and initialise Core and Memory parameters in a proprietary way. Which means you cannot use the normal driver coolbits or rivatuner methods of overclocking !
If you decide to flash with another manufacturers 5950u bios, then it may also be an idea to read the 59xxx bios modding guide for ideas on what other improvements are possible.