GeForce GTX 970: Correcting The Specs & Exploring Memory Allocation

Over the weekend we reported on a statement released by NVIDIA regarding recent concern over unusual VRAM allocation and VRAM bandwidth performance from the GeForce GTX 970. In brief, various GTX 970 owners had observed that the GTX 970 was prone to topping out its reported VRAM allocation at 3.5GB rather than 4GB, and that meanwhile the GTX 980 was reaching 4GB allocated in similar circumstances. All of this was at odds with what we thought we knew about the cards and the underlying GM204 GPU, as the two cards were believed to have identical memory subsystems.

As a result we’ve been digging into this issue over the weekend, working to collect the final pieces of the puzzle. To that end NVIDIA reached out to us Sunday evening to fully explain the issue at a level of detail necessary for our level of depth, making available to us a “triage team” of sorts of technical marketing, product management, and engineering/architectural personnel to answer questions and to better explain the issue. While there’s still some benchmarking left to do on our end – we’ve only had a relatively brief Sunday evening to work with NVIDIA’s full explanation – at this point we feel like we have a solid grasp of what’s going on with the GTX 970, how its memory segmenting and allocation work, and how it can impact performance.