When Nvidia launched the GTX 970 and 980 back in the fall of 2014, Maxwell quickly rose to prominence thanks to strong performance and excellent power efficiency. Early reviews showed good results on both cards, but deeper dives into the GTX 970 post-launch turned up troubling behavior: The card strongly preferred to limit its available memory to 3.5GB, not the 4GB it actually carried. A class-action lawsuit was launched a month after the problem came to light, and Nvidia has apparently resolved that case as of today.
Nvidia will pay each GTX 970 owner that applies an average of $ 30 (there’s no information yet on how one applies for the refund) in addition to paying $ 1.3 million in attorney fees, according to Overclockers3D. While $ 30 isn’t huge, it presumably accounts for the estimated value of the effectively-missing 512MB of RAM.
For those of you who don’t recall the details of the issue, the problem was this: The GTX 970’s internal memory configuration disabled one of its crossbar switches, as shown in the diagram below:
The “SM” blocks in this diagram are the actual processor cores, while the L2 blocks refer to the L2 cache. “MC” blocks are the memory controllers. The chip is designed so that any SM block could talk to any of the memory controllers, but three of the SM blocks and one of the L2 cache blocks is grayed out in this diagram. The SM blocks are disabled to hit the GTX 970’s core count target, but the last block of L2 cache does double duty, serving two SM blocks rather than just one. Disabling L2 cache blocks in this fashion also reduced the GTX 970’s ROP count to 56 down from 64 (as Tech Report noted at the time, actual throughput was actually a maximum of 52 pixels per clock due to associated limitations in the crossbar).
Nvidia PR claimed that the GTX 970’s original specs were miscommunicated to reviewers, and I believe them. There’s a difference between cherry picking results and arguments to favor any company’s given position on a topic, and flatly misrepresenting the capabilities of one’s hardware in an attempt to drive sales under false pretenses. The former is expected, the latter is criminal. The net effect of this problem was to leave the GTX 970 with a 512MB memory buffer that was technically available to games if absolutely required, but could only be accessed at a fraction of the speed of main memory, as shown in the results below:
Practically speaking, the impact on the vast majority of users was minimal. Benchmarks and tests showed that there were games that could trip the GTX 970, but this often only occurred at the limits of playable frame rates in any case. Overall, the GTX 970 sold well and became one of the most popular GPUs of the previous generation. Given that recent price cuts have left it priced as low as $ 260 (as of this writing), it’s not a bad deal even now — though generally speaking I’d still recommend either the RX 480 or the GTX 1060, depending on your preferences. While the GTX 970 should be fine for 1080p and below in the indefinite future, there’s always the chance that this RAM problem will bite as VRAM requirements continue to scale up.