Update: The Nvidia employee forum post, mentioned below, has been edited to remove any mention of a driver update designed to tweak the 970's memory allocation. Original story below.
According to an Nvidia employee on the company's forums, the graphics card manufacturer is working on a driver update to address the GTX 970's performance issues when utilizing more than 3.5GB VRAM.
In the last few weeks, commenters across the Internet uncovered that the GTX 970 only seems to use 3.5GB of its 4GB VRAM and encounters a serious drop in performance when pushed to (what should be) its limit, using all 4GB. Nvidia responded with a statement explaining how the GTX 970 uses a different configuration than the 980 and allocates its memory into a 3.5GB and a 0.5GB segment. The GPU has higher priority access to the 3.5GB section, but dipping into that secondary section can have a real impact on gaming performance.
Nvidia employee PeterS commented on the issue on the Nvidia forums yesterday, noting that a driver update is in the works that will "tune what's allocated where in memory to further improve performance."
The driver update will hopefully help, but while it might optimize performance, the architecture of the 970 can't be changed through software. The card won't be able to access that last 500MB of VRAM at the same speed as the GTX 980.
Regardless of the driver update, PeterS posted that "If you don't want the card anymore you should return it and get a refund or exchange. If you have any problems getting that done, let me know and I'll do my best to help." Keep in mind, though, that the GTX 970 is still an all-around great performer and overclocker. The impressive benchmarks of our original review haven't changed. Currently, few games require the full 4GB VRAM. But the card's limitation may make it less future-proof for games down the road.
If you're just catching up on the issue, check out our breakdown here.