AMD Radeon RX 6800 Review 112

AMD Radeon RX 6800 Review


Value and Conclusion

  • The AMD Radeon RX 6800 will retail for $580.
  • Tremendous performance gains
  • Faster than RTX 2080 Ti and RTX 3070
  • World-leading power efficiency
  • 16 GB VRAM
  • Idle fan stop
  • Quiet
  • Good overclocking potential
  • Multi-monitor power consumption improved
  • USB-C output
  • Hardware-accelerated raytracing
  • Support for HDMI 2.1, AV1 decode
  • PCI-Express 4.0
  • 7 nanometer production process
  • Raytracing performance loss bigger than on NVIDIA
  • RTX 3070 has better price/performance
  • Could be quieter
  • Memory overclocking artificially limited
Our launch-day coverage of the Radeon RX 6800 series includes: Radeon RX 6800 XT review, Radeon RX 6800 review, and AMD Smart Access Memory review.

AMD has achieved the unthinkable—they now have parity with NVIDIA. Just a few weeks ago, people thought NVIDIA was so far ahead that they couldn't be caught anymore. The new RDNA II architecture brings with it substantial improvements in every area, which made this achievement possible.

The Radeon RX 6800 beats both NVIDIA's RTX 2080 Ti and RTX 3070 by around 8–9%. Compared to the RX 6800 XT, which we also reviewed today, the difference is 15%, and RTX 3080 is 21% faster, but more expensive. Before AMD's announcement, I've heard people say "oh if AMD could only match the 2080 Ti, it would be huge win for them." Well, AMD's "Pro" variant, not "XT," has achieved that, which is very nice. NVIDIA's fastest, the RTX 3090, is 33% faster than the RX 6800, but almost three times as expensive. AMD has the RX 6900 XT ready for that, we'll know more details soon.

With these performance numbers, the Radeon RX 6800 is the perfect choice for 1440p gaming at well above 60 FPS. It can also be your gateway to 4K gaming. While it's not fast enough to get 60 FPS in every title at the highest settings, it's pretty close. If you reduce some detail settings, you should get 60 FPS easily. Things are different once you turn on raytracing, however. Just like on NVIDIA, there's a hefty performance hit when running with the DirectX Raytracing API. We only tested two games so far, but it seems the loss in performance is bigger than on NVIDIA, who improved in that area with Ampere. Remember, this is AMD's first-generation raytracing implementation. Performance is still very respectable. I expected RT performance similar to Pascal cards, where RT is emulated in shaders. RX 6800 does much better than that, I'd say we will see performance roughly around RTX 2080 levels, with big differences depending on the title. AMD has a clear advantage here—they are the hardware provider for the new gaming consoles, which have raytracing as one of their new features. This means game developers will optimize their games for this architecture's RT capabilities. What we've seen so far is that RT on consoles will be minimal, just some basic eye candy, but I'm sure developers will figure out new innovative ways in the coming years. NVIDIA is big on raytracing, which they have to be to keep their performance lead.

With Navi 21, AMD is introducing a new component to the gaming GPU world—an L3 cache is part of the Navi 21 GPU. While traditionally, the better use of die area was to add more shading units, this is different, now that power and heat is a problem. A cache does use a lot of die area, but also consumes very little power, which makes it an excellent idea when power constrained. The nature of GPU workloads can also benefit from an L3 cache—I expect we'll see it in all future generations, at various sizes. Our test results suggest that the efficiency of the L3 cache varies greatly between games and resolutions.

Over the years, I have criticized AMD almost every time for the weak performance of their cooler designs. Guess they listened as the coolers on the Radeon RX 6800 Series are much improved. While the XT uses a triple-slot cooler, the non-XT uses a dual-slot variant. For the RX 6800, this of course means there's less space for the heatsink to do its job. It still handles the heat output very well. With 70°C, temperatures are very low, and the hotspot sits at 83°C, plenty of headroom left there, too. AMD clarified that the hotspot is designed to operate at up to 110°C indefinitely, which it isn't even close to. This is a huge improvement over the Radeon RX 5700 Series, which did encounter high temperatures on some cards. Noise levels are good, too, much improved over previous AMD reference designs. While the RX 6800 XT is one of the quietest cards I've ever reviewed, the RX 6800 isn't that impressive. Sure, it's reasonably quiet at 34 dBA, but I feel noise levels could be better. Our apples-to-apples cooler comparison testing clearly shows that this cooler is superior to the RTX 3070 FE, so why is it louder? It seems AMD didn't properly tune the fan curve to their cooler's capabilities as it runs too fast for the heat output of the GPU. While that results in low temperatures, these really don't help you in any way. A few degrees warmer would have significant reduced noise output. Still, for a card in this performance class, noise levels are definitely nice. Just like NVIDIA's GeForce 30 lineup, idle fan stop is part of Radeon RX 6000, too; both reference designs will shut down their fans completely when the card is idle at the desktop or running productivity applications, and while Internet browsing.

The cornerstone for all these improvements is power efficiency. NVIDIA learned this with the GeForce GTX 480, AMD has learned it just now. It seems their primary design goal was to bring down energy consumption and the rest will follow. They doubled energy efficiency over the first-generation RDNA architecture, which makes them considerably more efficient than even NVIDIA Ampere. We measured an average power draw of just 223 W during our Metro Last Light power test, which is a mix of lighter and highly demanding scenes. That's why I picked it many years ago, because it highlights a GPU's ability to quickly react to load changes to conserve energy. To put things in perspective, this is the same power draw as RX 5700 XT, Vega 56, GTX 1080 Ti, RX 590 (!), or RTX 2080—at much higher performance of course. The secret sauce for the fantastic energy efficiency of the RX 6800 is that AMD is clocking it lower, which means it can also run at a lower voltage, both of which improve efficiency. I didn't think I would see the day AMD fixes its multi-monitor power consumption. Finally, the memory no longer runs at full speed in that scenario, which greatly reduces power. Down to 7 W, it is now much better than NVIDIA. A weak point is media playback, which now runs memory at full speed, resulting in almost 50 W power consumption. This looks like a driver bug, though.

Much has been talked about VRAM size during NVIDIA's Ampere launch. The GeForce RTX 3080 has 10 GB VRAM, which I still think is plenty for today and the near future. Planning many years ahead with hardware purchases makes no sense, especially when it comes to VRAM—you'll run out of shading power long before memory becomes a problem. GTX 1060 will not drive 4K, no matter whether it has 3 or 6 GB. Game developers will certainly make use of the added memory capacity on the new consoles, we're talking 8 GB here, as a large portion of the console's total memory is used for the OS, game, and game data. I think I'd definitely be interested in an RX 6700 Series with just 8 GB VRAM at more affordable pricing. On the other hand, AMD's card is cheaper than NVIDIA's product and has twice the VRAM, so there is really no reason to complain.

With the RX 6000 series, AMD introduced the "Rage Mode" feature, which automatically boosts clock speeds beyond specifications. Unfortunately, only the RX 6800 XT and upcoming RX 6900 XT get it. If you read our RX 6800 XT review, you're not missing out on much.

Priced at $580, the Radeon RX 6800 feels a little bit expensive. It goes up against the GeForce RTX 3070, which costs only $500. Yes, RTX 3070 is slightly slower, but makes up for it with slightly better RT performance and a quieter cooler on the Founders Edition. On the other hand, AMD is giving you 16 GB VRAM, which definitely add to the design cost. Across some AMD marketing material, we read the RX 6800's specs to be "Up to 16 GB memory," which implies a cheaper 8 GB variant is possible. AMD's card also has a much more complex cooler and PCB design. Still, at the end of the day, I'm not sure if that can convince buyers who only care about FPS in both rasterization and raytracing. Performance differences do vary wildly between titles, so check the engines of the games you're playing, we've got all the major ones covered in this article. While AMD's pricing seems a bit high, I feel like the card will still sell out quickly because it offers a very competitive solution that is on par with NVIDIA's lineup—who would have expected that just a few weeks ago?
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