“The GPU has higher priority access to the 3.5GB section.”
Following up on a story regarding user complaints based on problems with Nvidia’s GTX970 card, which “prevents users from efficiently allocating more than 3.5GB’s at a time”, Nvidia has issued a statement.
The Nvidia moderator, who goes by the forum name of ManuelG, said “The GeForce GTX 970 is equipped with 4GB of dedicated graphics memory. However the 970 has a different configuration of SMs than the 980, and fewer crossbar resources to the memory system. To optimally manage memory traffic in this configuration, we segment graphics memory into a 3.5GB section and a 0.5GB section. The GPU has higher priority access to the 3.5GB section.”
The statement draws on, but this means that even though there is technically 4GB of memory available, no more than 3.5GBs can be allocated to the game when it requires less than that, effectively limiting higher end games that can make use of uncompressed textures and other VRAM hungry assets.
This is nothing new as similar odd VRAM usage claims have popped up numerous times across other older GPU’s.