FSR Redstone's Strange Debut: Ray Regeneration tested in Black Ops 7

FSR Redstone ray regeneration, the ray tracing denoising technology that AMD is pursuing as an alternative to Nvidia's DLSS ray reconstruction, went live last week with a bit of a thud. Instead of enjoying a gentle rollout or an advanced preview, AMD surprise-slapped Redstone into the launch version of Call of Duty: Black Ops 7, complete with some bizarre limitations on how you can actually use it. For reasons that aren't completely clear, the option only works in multiplayer and zombies modes, along with the game's internal benchmark sequence.

Thus, we scrambled to test how this live model compares to AMD's proclamations from earlier this year - albeit with a touchy, unideal implementation inside of a game's online mode, which boots you back to the menus if you don't touch the controller for 30 seconds - great for comparison shots! But test we did, and the results do show some promise but there's the sense that there's more to come from the final iteration of the technology. Not least, we need to see more features. Ray regeneration is just one part of FSR Redstone. FSR 4 is another, as is an ML-based frame generation solution, along with neural radiance caching. So, it's just FSR Redstone ray regeneration on offer in Black Ops 7.

Testing presented a number of challenges. As we quickly found out, turning on AMD's ray regeneration feature inside of Black Ops 7 is not currently a 1:1 match for the equivalent Nvidia technology. Yes, we should expect visual differences, but there are actually foundational differences in what the FSR and DLSS techniques are attempting to achieve. For starters, AMD's model only applies to reflections, as opposed to full-scene coverage you might expect when thinking about ray reconstruction's impact on a full image in the wide number of games that already support Nvidia's version.

When turned on, Black Ops 7 also presents vastly different image output characteristics on AMD GPUs than it does Nvidia ones. Shadow cascade distance differs and their qualities vary, with AMD's closer-to-camera shadows having more opacity and Nvidia's having more darkness. The ray tracing model differs as well, with lights and other rays reflected in Nvidia's presentation which are missing from AMD's which calls into question supposedly like-for-like testing between vendors. The same goes for accounting for various bugs and crashes, which we can't immediately chalk up to AMD or even the COD development teams.

In another surprising discovery, we've confirmed that Redstone ray regeneration can be paired with any available upscaler inside Black Ops 7, not just the most recent FSR 4. This is interesting to us because Nvidia deliberately combines its own AI-driven denoising pass with its DLSS upscaling process, which we understand benefits both image quality and performance. That shows on the converse side, sadly, as Redstone's reflections have no upscaling of their own and show up with sub-native resolution artefacts.

There's a chance AMD leaves this as-is, but based on limited information from the firm at the moment, we cannot confirm owing to a lack of information. We're still waiting for an introductory blog post from AMD as of this article's publication, which, honestly, might not even come until Redstone's previously announced formal launch date of December 10.

Still, we can't help but believe that AMD Redstone, like AMD Frame Generation before it, has somehow launched in a work-in-progress state. We draw that conclusion in part because its reflections are missing a key real-life attribute: a narrowing of fine detail at the point of reflective contact, followed by increasing reflection blur as the distance widens. This issue breaks much of the inherent realism of a quality ray-traced reflection model, with this concept of "contact hardening" being inherent to the look.

However, AMD deserves kudos in one rendering aspect. Redstone ray regeneration does a solid job in its current state picking up movement and animations in reflections, as evidenced by a number of video projections seen in reflections on damp surfaces in Black Ops 7's training instance (a fixed environment we could more firmly test Redstone on than a live multiplayer session). Direct comparisons with DLSS ray reconstruction show less ghosting of animated objects in AMD's reflections. Similarly, the AMD presentation displays less smearing of a reflected object's silhouette than Nvidia's.

But that doesn't mean AMD wins in all animation aspects, particularly disocclusion artifacts. Move an object like a gun into and out of the frame, and that object's silhouette will be held inside a reflective surface longer in the AMD presentation.

Though we don't completely love AMD's ray regeneration presentation so far, we can't complain about performance. It only costs 1fps across multiple benchmark runs - whether attached to FSR 3 or FSR 4 upscaling - when compared against Black Ops 7's own denoiser. In an ideal world, as AMD refines its machine learning model to better account for Redstone's launch-week issues, this performance cost might remain slim while offering better visual results in the future, but we can only guess on that front at this time.

Still, FSR Redstone's ray regeneration debut comes across as a touch strange and incomplete and we can't help but have expected more from our first contact with a key new machine learning-based technology. Perhaps everything will become clearer after AMD's December 10th presentation, but in the meantime, we're left testing a very limited, multiplayer-only version of a rendering pipeline that could eventually be a difference maker for AMD. For now, the jury's out.