Nvidia Release Statement Regarding GTX 970 VRAM Issue

There’s been a hot debate on this last few days, why is the GTX 970 on showing 3.5GB of VRAM, instead of the full 4GB?

As far as we know, the VRAM is split between two sections. The first houses 3.5GB of high priority memory, the second holds 500MB. Games can still use all 4GB, but it switches back down to 3.5GB when not needed.

Nvidia moderator ManuelG made the following statement.

“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. When a game needs less than 3.5GB of video memory per draw command then it will only access the first partition, and 3rd party applications that measure memory usage will report 3.5GB of memory in use on GTX 970, but may report more for GTX 980 if there is more memory used by other commands. When a game requires more than 3.5GB of memory then we use both segments.

We understand there have been some questions about how the GTX 970 will perform when it accesses the 0.5GB memory segment. The best way to test that is to look at game performance. Compare a GTX 980 to a 970 on a game that uses less than 3.5GB. Then turn up the settings so the game needs more than 3.5GB and compare 980 and 970 performance again.”

They also released the following chart, which shows that there is no performance drop when addressing the extra 500MB of VRAM.

So there you have it, there’s no issues here and that’s how the card is supposed to operate; it just looks a bit strange.

Thank you DSO for providing us with this information.

Images courtesy of DSO.