Yet I will say this in its favour: The RX 6900 XT delivering anything close to RTX 3090 performance is something of an engineering marvel from a company that for the longest time has washed its hands of high-performance graphics cards in favour of the volume mid-range market. The AMD RTG (Radeon Technology Group) has set itself up with a solid foundation with the so-called 'Big Navi', if only as a point to build upon with the coming generations. The RX 6900 XT is confirmed to launch on 8 December 2020, which means we’re just over a month away from release.

The Radeon RX 6900 XTX is a graphics card by AMD, that was never released. Built on the 7 nm process, and based on the Navi 21 graphics processor, in its Navi 21 XTXH variant, the card supports DirectX 12 Ultimate. This ensures that all modern games will run on Radeon RX 6900 XTX. Additionally, the DirectX 12 Ultimate capability guarantees support for hardware-raytracing, variable-rate shading and more, in upcoming video games. The Navi 21 graphics processor is a large chip with a die area of 520 mm² and 26,800 million transistors. It features 5120 shading units, 320 texture mapping units, and 128 ROPs. The card also has 80 raytracing acceleration cores. AMD has paired 16 GB GDDR6 memory with the Radeon RX 6900 XTX, which are connected using a 256-bit memory interface. The GPU is operating at a frequency of 2075 MHz, which can be boosted up to 2435 MHz, memory is running at 2250 MHz (18 Gbps effective). Then at 4K, the 6900 XT is 40% more costly per frame when compared to the 6800 XT, though it's almost 30% better value per frame than the RTX 3090. Still, with the RTX 3080 and 6800 XT offering a similar level of value, it's fair to say the 6900 XT is terrible and the RTX 3090 is horrendous. Bottom Line AMD claims the RX 6800 XT is capable of reaching 150fps for Doom Eternal, 122fps in Battlefield 5 and 169fps in Forza Horizon 4, all of which are running at 4K resolutions. The latest Radeon™ Software Adrenalin 2020 Edition unleashes the full potential of your GPU with day-0 drivers optimized for new game releases and a highly customizable gaming experience. Here the RX 6900 XT delivered playable, post 60fps, speeds in every resolution running the game’s internal benchmark. It failed to offer a significant lead on the cheaper RTX 3080, however, which is slightly surprising.At 4K, that lead worsens over the RTX 3080, where the RX 6900 XT falls within a single percent of the cheaper card, and the RTX 3090's lead grows to just under 10 percent. Another example would be Fortnite which is basically broken with RT enabled on the 6900 XT in terms of performance. The performance hit is pretty disgusting on the RTX 3090 as well, and even DLSS struggles to get us anywhere near native performance. This title becomes visually impressive with RT enabled, but it's not a game you'd necessarily play with this feature turned on given its fast paced action and need for high fps.

At 4K, the RX 6900 XT struggles to get anywhere close to the RTX 3090, and often falls even behind the RTX 3080 in titles where AMD's graphics cards are less suited. Whether that's set to change with future titles is hardly a consideration we can make today, but even so it only furthers the erratic performance we're already seeing game to game. When looking at performance per watt we see that the 6900 XT is only slightly better than the RTX 3090. AMD is confident that the 16GB of VRAM across its high-end cards today will come into play more and more with the coming wave of videogames. That's a little nebulous to base a review on right now, even if it's likely to be realised in some form of another eventually. Instead you can guarantee some performance uplift from Rage Mode and Smart Access Memory—two features that generate a slight boost to performance. Here the RX 6900 delivered solid post 60fps speeds across the board with ray tracing turned off, exceeding the 3080 by over 10fps in 4K. Performance fell behind the Nvidia card with it turned on, where it once again fell dangerously close to below 30fps speeds in 4K.

Power

We're once again looking at 128MB of Infinity Cache with the RX 6900 XT, the same found with all RX 6000-series cards so far, and that which AMD touts as enough to successfully prevent a slower call to external memory some 60-80 percent of the time. That's all without dramatically increasing die size, cost, or power requirements, it says. Infinity Cache is more effective at lower resolution, too, although seeing as 1080p is less memory intensive than 4K that doesn't always work out as the simple equation it perhaps sounds like.

Then at 4K we're looking at a 12% performance increase for the 6900 XT over the 6800 XT, but that meant it was still 10% lower than the 3090. Using Nvidia's PCAT we also see that the 6900 XT uses slightly more power than the 6800 XT – about a 1% increase in power usage – which may be down to the 6900 XT using higher quality silicon. When compared to the RTX 3090, the 6900 XT consumed 14% less power, though it's also slower in Doom which we use for this test. Then at 4K, the 6900 XT was 8% faster than the 6800 XT which meant it trailed the RTX 3090 by a 7% margin. Perhaps the most noteworthy function added with RDNA 2 is ray tracing capability, however, made possible by the inclusion of AMD's Ray Accelerators. The 1440p gains are ever so slightly improved. The 6900 XT is on average 8% faster than the 6800 XT and just 2% faster than the 3090.It doesn’t have an internal benchmark so we gauged performance by taking an average fps count running through a section of the Nordalys War Story. The same Navi 21 GPU resides within the Radeon RX 6900 XT as the two RX 6800-series graphics cards we've already reviewed, meaning you're getting an identical, and very effective, dual compute unit configuration that's tailor-made for gaming—albeit on a slightly larger scale with the 80 CU RX 6900 XT. That makes for a total of 5,120 stream processors—an 11 percent increase over the RX 6800 XT. However, RDNA 2’s ray tracing works a little differently to Nvidia’s. Architecturally this is because the two companies achieve ray tracing using different methods: AMD does it by loading dedicated ray-tracing accelerators to its cards, while Nvidia powers it with custom RT cores.

Doom Eternal saw the 6900 XT delivering a 7% performance boost from the 6800 XT at 1440p, though that meant it was still 4% slower than the 3090. The margin to the 3090 grew at 4K as here the 6900 XT was 9% slower, though it was also now 9% faster than the 6800 XT.

Performance Summary

For those targeting low resolution, high refresh rate gaming the Radeon RX 6900 XT is a better choice than the GeForce RTX 3090, though it's typically not that much better. It's also not much better than the 6800 XT... we're talking about a 5% boost on average. Frankly, the RX 6900 XT hardly stood a chance. Which I now fear should've been obvious from the very beginning.