NVIDIA Turing’s Tensor cores can be a bottleneck at higher framerates
When NVIDIA’s Deep Learning Supersampling (DLSS) was announced, it was almost as if it was a godsent. NVIDIA promised higher frame rates by harnessing the Tensor cores in the Turing GPUs. We are all for higher frame rates, so why not, right?
Well it seems that there are a number of limitations to the technology. As TechPowerUp found out, NVIDIA is not allowing certain cards from turning DLSS on at certain resolutions. It appears that NVIDIA wants your frame rates be below a certain threshold before you can enable DLSS to boost your FPS. For example, you can’t enable DLSS at 1440p or even at 4K sans DXR if you are running a GeForce RTX 2080 Ti in Battlefield V.
In our testing, a GeForce RTX 2080 Ti delivers an average of 83 fps at 4K without DXR, and around 75 fps at 1440p with DXR enabled. That’s pretty good, but if we could tap into the 40% performance boost that DLSS promises, it would be great for high refresh rate gameplay. It seems that it wasn’t to be, as the Tensor cores would have a problem keeping up at those frame rates.
TechPowerUp’s testing also included Metro Exodus, which confirms the idea that the Tensor cores can be a bottleneck, and the number of Tensor cores will also be a factor in that. For example we see that DLSS is not offered in Metro Exodus for the GeForce RTX 2060 at 4K, but is available at 1440p with DXR on.
As resolution goes up, the amount of data that the Tensor cores will have to process will increase significantly as well. At 4K, the Tensor cores will be handling higher resolution visuals than it would at say 1440p or 1080p. More pixels means more data, and more data would naturally take longer to process.
When your card is able to push out a higher framerate at a respective resolution, it also means that you will have shorter frametimes. That would leave very little time for the Tensor cores in your GPU to process DLSS. In those situations, NVIDIA would rather you not be able to use DLSS instead of you complaining that DLSS causes you to experience worse framerates.
So I guess a single GeForce RTX 2080 Ti will still be unable to properly push the ROG Swift PG27UQ at 4K 144 Hz…
Pokdepinion: Perhaps updates to the drivers and games would enable DLSS at higher framerates, just like how an update to BFV made DXR much more playable…