Radeon RX 6800 XT vs GeForce RTX 3080 • Eurogamer.net

AMD’s new RDNA 2 architecture has arrived for desktop PCs via the RX 6000 line of graphics cards, and it’s a major release, bringing with it full hardware support for the DirectX 12 Ultimate feature set, including the DXR API. . Yes, ray tracing is now an integral part of AMD’s high-end parts, and we wanted to monitor how effective the Radeon version of the technology is in the RX 6800 XT, and how it compares to its closest rival, the RTX 3080. Benchmarks have shown that Nvidia’s second-gen tech is faster than AMD’s debut offering, but what’s the full story here?

To help put this piece together, XFX sent me a factory overclocked example of the RX 6800 XT, specifically the Speedster Merc 319 edition of the card. Using its own three-fan cooler design, this monster card offers boost clocks rated at 2340MHz, about five percent higher than the reference model, but I’ve seen it routinely hit clocks in the 2400MHz range and plus. While the XFX card is rebranded, the design philosophy has a lot in common with its previous ‘THICC’ range. The cooler is certainly similar and does a good job of keeping temperatures in the low 70 degree Celsius range under load. However, as I mentioned, it is somewhat beastly in terms of form factor. Certainly, in terms of its sheer volume, you need to make sure you have adequate space in your box – it is around 34cm or 13.5 inches long!

In terms of actual ray tracing metrics, best to check out the video here for a full breakdown of how I tested the individual RT effects and how well they handle on each of our competing GPU architectures, but the goal The key to this test was to isolate the individual stages of the RT pipeline to see how Nvidia and AMD work, and to do so within the context of three key RT effects: shadows, reflections, and global lighting.

Typically, in any RT scenario, there are four steps. For starters, the scene is prepared on the GPU, filled with all the objects that can potentially affect ray tracing. In the second step, lightning bolts are fired at that scene, passed through it, and tested to see if they hit objects. Then there is the next step, where the results from step two are shaded, such as the color of a reflection or whether a pixel is in or out of the shadow. The last step is to remove noise. You see, the GPU cannot send unlimited amounts of rays to track; Only a finite amount can be traced, so the end result seems quite noisy. Noise removal softens the image and produces the final effect.

Therefore, there are numerous factors at play when dealing with RT performance. Of the four steps, only the second is hardware-accelerated, and the actual implementation between AMD and Nvidia is different, and GeForce cards have additional hardware. RDNA 2 calculates lightning path in compute units, introducing competition for resources, while Nvidia does it in a specialized processor within the RT core. The first configuration stage can have significant CPU requirements, while the shadowing and denoising steps can have specific preferences for certain GPU architectures. For example, Quake 2 RTX and Watch Dogs Legion use an Nvidia-built noise eliminator, and while it won’t have been designed to malfunction on AMD hardware (which Nvidia wouldn’t have had access to when they coded it), it’s certainly designed to run what best possible on RTX cards.

Regardless, in the video I intend to be comprehensive in addressing the entire ray tracing process on both architectures, covering a variety of effects. Ray-traced shadows are tested in Call of Duty: Black Ops Cold War (an Nvidia sponsored title) as well as Dirt 5 (supported by AMD). I take a look at the ray traced reflections in Ghostrunner in Unreal Engine 4, where I can examine the effect with some degree of adjustment and of course the reflections from Watch Dogs Legion are also put under the microscope. I chose this because AMD RT hardware is used in consoles to deliver the effect, plus through mod I can access both the console and Nvidia’s noise eliminators. With global ray-traced lighting, 4A Games’ amazing Metro Exodus is thoroughly tested, while I look at a more extreme example through the path-traced Quake 2 RTX, which now works on both AMD and Nvidia RT hardware, thanks. to the integration of finalized Vulkan RT Extensions.

So what is takeout food? I think here are some interesting results. Ray-traced shadows are generally economical on resources on both the RX 6800 XT and RTX 3080, and the RTX 3080 makes minimal gains at lower settings, which then increase as the quality of the ray-tracing increases on settings. higher, in a game like Call of Duty Black Ops. For ray-traced reflections, the effect is much more demanding on the GPU hardware, but the visual gain is more pronounced in many scenarios. The greater the randomness of the reflected rays and the greater the number of rays fired, the higher the performance of the RTX 3080 compared to the RX 6800 XT, accounting for almost half the time in certain configurations. However, the efficiency advantage of the RTX 3080 diminished after a certain inflection point, and I saw the same with global illumination – the RTX 3080 could render the effect in almost half the time on Metro Exodus, or even a third of the time on Quake 2 RTX, but by increasing the amount of lightning after this the RTX 3080 had less of an advantage.

Overall, from these tests, it appears that the simpler the ray tracing, the more similar the effect render times are between competing architectures. The Nvidia card is undoubtedly more capable across the RT pipeline, and the RTX 3080 appears to have less dramatic performance losses as ray tracing complexity increases, but on the less complex end of the scale, AMD it is competitive. Meanwhile, PlayStation 5’s Spider-Man: Miles Morales demonstrates that Radeon ray tracing can produce some impressive results in more challenging effects, and that’s using a GPU that is significantly less powerful than the 6800 XT. And with that in mind, we must accept that ray tracing on the PC side is still in its infancy, especially when running on AMD hardware. At this time, I can only offer general conclusions from a representative, but still small, sample. So far, we’ve only seen RT shadows in AMD sponsored titles, and I’m looking forward to seeing future titles play out in collaboration with Team Red on demanding RT effects. While ray tracing has been with us in the PC space for over two years, the story is just beginning and I can’t wait to see what comes next.