The latest Nvidia GeForce driver update has removed the options to overclock and underclock the mobile series 900 GPUs.
Adding insult to injury, Nvidia told complaining customers on its official forums that this option was enabled in earlier drivers by accident and that removing it is the right thing to do. The company argued that laptop GPUs are not designed for overclocking and that by doing so, users risks serious damage to the graphics chipset as well as to the whole laptop.
"Unfortunately GeForce notebooks were not designed to support overclocking. Overclocking is by no means a trivial feature, and depends on thoughtful design of thermal, electrical, and other considerations," explained Nvidia. By overclocking a notebook, a user risks serious damage to the system that could result in non-functional systems, reduced notebook life, or many other effects."
Nvidia's argument isn't really convincing as overclocking isn't officially supported and is being done at the user's risk. On the other hand, there is no denying that overclocking a laptop GPU with limited airflow and cooling is a lot more dangerous.