Nvidia's GeForce GTX ray-tracing driver is here but try not to expect too much
Better to be pleasantly surprised if it's worth going "DXR on" with your old card.
Nvidia announced at this year's Game Developer's Conference that it would be bringing DirectX ray tracing (DXR) support to its older Pascal-based graphics cards, so it's time to buckle in: The drivers are now ready for download. But you may not find the tradeoff between performance and the potentially enhanced quality worth it.
The Pascal-generation GTX cards supported include:
Titan XP
Titan X
GTX 1080 TI
GTX 1080
GTX 1070 TI
GTX 1070
GTX 1060 6GB
The Volta-based Titan V and Turing-based GTX 1660 and 1660 TI are also supported. You'll be able to get the Game Ready driver via GeForce Experience or on GeForce.com, along with some new whizzy demos.
The new generation of RTX GPUs based on Nvidia's Turing architecture arrived last summer, bringing two headline features: processing cores devoted to ray tracing (RT cores) -- the same kind of rendering that's used in almost every 3D animation -- and Tensor cores for accelerating the neural network processing which underlies DLSS (Deep Learning Super-Sampling), Nvidia's new AI-based scaling algorithms which more realistically simulate detail when the graphics processing load starts to punish performance.
A less glamorous advance is the concurrent floating-point execution pipeline, which improves overall performance with parallel processing for the myriad calculations which underlie rendering.
Ray tracing can make games look better, providing more realistic reflections and shadows, with a lot less work for the developers: The less manual tuning for individual scenes they have to do the more they'll be able to concentrate on improving the overall visual quality of the game.
The DXR programming interface makes ray tracing easily scalable for developers. In other words, they can define rules which determine how to prioritize rendering tasks like reflections and shadows and to what level of accuracy. DXR then applies those rules based on how powerful your hardware is.
By opening DXR to the vast installed base of older GTX cards, developers have a lot more incentive to incorporate ray tracing into their games, without any extra work, than they have for the small number of pricey RTX GPUs in laptops and desktops .
But here's where the technical nonsense matters. Pascal-based cards, because they have no RT cores, are really not up to the processing challenges of full-on ray tracing, so DXR will dumb down the effects to fit within the capabilities of the card. And even then you'll still be taking a performance hit -- for effects that may be so subtle as to not be worth it.
And it seems like the more noticeable the effect, the more processing it tends to require, with reflections (we like the shiny shiny) and global illumination (which can simulate the changing light over the course of a day, for example), being the most demanding.
The newer priced-to-sell Turing-based GTX 1660 and 1660 Ti don't have any RT cores either. What they do have is the improved floating-point performance. So they'll still take a performance hit in exchange for slightly better realism, just not as much as some of the older cards.
While ultimately I think ray tracing will become common -- it always takes some time for new hardware technologies to ramp up and prices to come down -- it's possible that opening it up to cards that can't do it justice may backfire. Though Nvidia's working hard to manage expectations, I think the exercise will leave a lot of gamers with an "is that all there is?" letdown rather than a "this is so worth plonking down $350 to upgrade to RTX!" attitude. We'll have to wait and see what actual gaming reveals.
