It was recently revealed that Nvidia's newest GeForce notebook drivers, versions R350 to R352, had re-introduced a restriction on overclocking of mobile series GTX 900M GPUs, this incident followed hot on the heels of a similar saga that occurred in February and sparked community outrage. Nvidia has, however, been very quick to respond to the latest development and address community concerns with decisive action.
The company released a new HotFix driver, version R353.00, which addresses recently discovered overclocking limitations. Nvidia claims the driver "fixes a regression that prevented overclocking the GPU on some GeForce Notebooks" and enables GeForce notebook owners to overclock again without driver restrictions. There is still, however, the potential for vendor-implemented vBIOS restrictions on overclocking where notebook vendors feel a particular notebook isn't capable of supporting overclocking functionality but, importantly, there are no driver-related restrictions from Nvidia's side.
Nvidia explained that the loss of overclocking functionality was not an intentional move, the company explained that “this was an error and is now being fixed, we’re sorry for the inconvenience caused and an updated driver will be available shortly”. The HotFix driver provides an immediate solution to the problem or customers can revert back to an earlier version of the driver where overclocking support was present. Future versions of Nvidia's mobile GPU drivers are expected to retain overclocking support that customers had previously enjoyed.