NVIDIA officially stated that there won't be an update specifically for the GTX 970, which is understandable as the reason why the latter 500MB of the card's GDDR5 memory is slower isn't due to a software issue but part of how the card is designed.
A couple of days ago, we informed you about NVIDIA’s plans to release a driver update that will tune what’s allocated where in memory to further improve performance. While those were the exact words of NVIDIA’s forum moderator, it appears that the company won’t release any driver specifically for the GTX970.
@DeadSanto123 We are always improving performance through drivers but there are no plans for an update specifically for the GTX 970.
— NVIDIA GeForce (@NVIDIAGeForce) January 29, 2015
Source: DSO Gaming