Nvidia Enables Ray Tracing on GPUs It Claims Can’t Ray Trace Effectively
When Nvidia launched the RTX family, the company’s messaging on GPU ray tracing performance was clear: The new RTX cores inside Turing GPUs were essential to high ray tracing performance, not because ray tracing literally requires them — it does not — but because they represented the only way to wring acceptable real-time performance out of the feature. Now, Nvidia has announced it will extend ray tracing support to its older Pascal family. Notably, it has not promised that such support will be particularly functional.
Nvidia’s blog post positions this as a win-win situation for both GTX gamers and RTX adoptees. GTX owners “have an opportunity to use ray tracing at lower RT quality settings and resolutions, while GeForce RTX users will experience up to 2-3x faster performance.” Given that ray tracing incurs a 30-50 percent performance hit on RTX GPUs, the chances of seeing playable frame rates with ray tracing enabled, even on a GTX 1080 Ti, are not high.
In fact, Nvidia’s entire blog post seems mostly calculated to persuade people not to run ray tracing workloads on GTX GPUs. The company takes multiple opportunities to note that the ray tracing portion of the rendering algorithm runs up to 10x faster on RTX cards, and that by enabling DLSS, RTX 2080 GPUs are up to 3x faster than GTX 1080 Ti GPUs.
According to Nvidia, attempting to run ray tracing on a GTX GPU will send the frame rate cratering, all the way down to 18fps on a GTX 1080 Ti. Of course, there are a few caveats to that. First, the 1080 Ti is using 1440p, despite the fact that 1080p was a target resolution for the RTX 2080’s ray tracing support to start with. Second, the 1080 Ti is using ray tracing set to Ultra. These aren’t the comparison points you’d use if the goal was to showcase that the 1080 Ti can deliver ray tracing. They’re the comparisons you use to show how the GTX 1080 Ti can’t actually deliver ray tracing, because you want to push gamers towards buying RTX cards.
Shadow of the Tomb Raider and BFV should deliver something closer to playable frame rates on a 1080 Ti, even at the detail settings Nvidia has chosen. The company’s own graphs show them hitting ~30fps in SotTR and a bit more than 40fps in BFV. Lower the resolution to 1080p and drop the RTX implementation to a lower level and frame rates may even approach playable.
Nvidia’s Ray Traced Dilemma
Nvidia, to be fair, is in something of a bind. The company has admitted that sales of its RTX family have been lower than expected, thanks to a significant cryptocurrency hangover and a glut of hardware on the market. Bringing DXR support to the GTX family lets Nvidia offer ray tracing as an option on GPUs that will never be able to support the feature, but can demo it for existing gamers in a slideshow. This, in turn, will let the company focus on DXR as an upsell for existing GPUs. Gamers who can’t enable RTX at all won’t see the benefits they’re missing. Gamers who can enable RTX but can’t actually play the game with this eye candy enabled might be more inclined to upgrade. As an added bonus, 1080 Ti owners might actually be able to trade large amounts of performance for improved visuals (the impact of enabling RTX is high enough that it seems doubtful anyone below a 1080 Ti owner will see playable frame rates).
RTX, not GTX, is the future of Nvidia products. As such, Nvidia is attempting to bring some of that capability back to its older cards, to entice gamers to upgrade. But RTX support remains confined to a handful of games and the Turing family has now been in-market for six months.
Nvidia’s efforts to paint RTX as an unvarnished breakthrough for GPU rendering have foundered on the rocky shoals of objective reality. But game developers won’t adopt a feature if there’s no support for it, and support is built through GPU sales — sales which, according to the Steam Hardware Survey, are sharply off Pascal adoption rates last generation. So Nvidia is hoping that by seeing RTX support on GTX cards, consumers will respond more strongly.
Our take remains the same. Gamers who buy into the RTX family should be aware that first-generation support for leading features is often underwhelming in the long run. We still expect to see 7nm GPUs arrive sooner than later, and the affordability of this current GPU generation has been anything but impressive. Giving more customers the opportunity to test RTX features is a solid move, but we don’t expect to see much in the way of playable frame rates. Nor does Nvidia have any reason whatsoever to provide them. The point is to push players into upgrading, not offer acceptable performance on older hardware. This is not to say that Nvidia would take steps to cripple the performance of ray tracing on older GPUs, but they certainly don’t have any reason whatsoever to optimize it.