AMD Announces Radeon RX 7900 XT & XTX Based on RDNA3 Architecture

AMD has announced its new generation of video cards based on the RDNA 3 architecture. The Radeon RX 7900 XT and Radeon RX 7900 XTX are the new top models that are the first gaming GPUs to use chiplets. The cards will be released on December 13.

With the Radeon RX 7000 series video cards, AMD brings the RDNA 3 architecture with significant improvements over the previous generation. The manufacturer says that during development it has emphasized good performance per watt without sacrificing better gaming performance. According to AMD, the performance per watt is up to 54 percent higher at RDNA 3 than at RDNA 2.

Chiplets on a GPU

By far the biggest change we see with the new Radeon cards is the move from a single, monolithic chip to multiple chiplets. Just like AMD has been doing with Ryzen processors for several generations, the manufacturer uses multiple chips and combines them into one cooperating whole. The Radeon RX 7900 XT and XTX are based on the Navi 31 chip. A maximum of 7 chiplets are combined on this, of which the Graphics Compute Die is the largest chip and contains all stream processors. This single GCD is surrounded by smaller chiplets called Memory Cache Dies, which contain the Infinity Cache, as well as a 64bit memory controller to the GDDR6 memory.

As on the RDNA 2 video cards from the RX 6000 series, AMD again uses Infinity Cache as a memory buffer between the graphics chip and the GDDR6 video memory, but this connection is of the second generation and therefore considerably faster. AMD states that the maximum bandwidth at 5.3TB/s below the line is 170 percent higher than with the memory arrangement on the previous generation. The amount of Infinity Cache has decreased from 128MB on Navi 21 to 96MB on the new Navi 31 chip, which, thanks to smarter memory use, does not result in a loss of performance, but does make a difference in energy consumption.

New compute unit, faster ray tracing and AI

The compute unit in RDNA 3 is equipped with a dual issue SIMD unit, with which AMD roughly makes the same adjustment as Nvidia has done with its Ampere architecture. Any stream processor can now work simultaneously on a floating point, integer or ai task. It is still unclear how flexibly the new compute unit can organize and distribute this work, but the theoretical computing power is at least doubled with this step. With this adjustment AMD does not specify the number of calculation cores twice as high, as Nvidia has started to do with its CUDA cores. With the placement of two AI accelerators per compute unit and the addition of new instructions, the performance in this area should be 2.7 times higher than on RDNA 2.

Disconnected Clock Speeds

To get the performance per watt as high as possible, AMD has decoupled the clock speeds of the shaders and the front end in the design of Navi 31. According to the manufacturer, high clock speeds of the front end are important for performance, but the shaders themselves can run slightly slower without reducing performance. On the RX 7900 XTX it was decided to have the shaders work at a maximum of 2300MHz, while the front end of this chip works at 2500MHz. The manufacturer states that it chooses the best balance because the clock speeds are effectively 15 percent higher than on the previous generation, while at the same time saving up to 25 percent in energy consumption.

Radiance Display Engine

With the RX 7000 series, the display output also gets a major update, which AMD has even renamed the Radiance Display Engine. The new generation Radeons feature the brand new DisplayPort 2.1 standard and can output 12bit per channel. With DP 2.1, thanks to an enormous bandwidth of 54Gbit/s, according to AMD, it is possible to control an 8k screen up to 165Hz or a 4k screen up to 480Hz with dsc. That’s a huge step over DisplayPort 1.4, as used on the RX 6000 series as well as on Nvidia’s new RTX 40 series cards. With DP 1.4, the compression limit is for 8k at 60Hz and for 4k at 240Hz. During the presentation, the manufacturer liked to emphasize this advantage in connectivity compared to its competitor.

Media Engine, FSR 3 and Hypr-RX

With the RX 7000 series, AMD is bringing AV1 encoding support to its graphics cards for the first time. The new Media Engine should also enable better video encoding through the use of AI, although the manufacturer does not yet provide details on how this is done exactly and whether the AI ​​accelerators are used for this. However, SmartAccess Video is introduced, where a Ryzen 7000 processor and Radeon RX 7000 video card combined can perform a heavy encoding or decoding task at an accelerated rate.

During the presentation, AMD briefly mentioned that a new version of FSR is coming, with an expected launch sometime in 2023. Under the name FSR 3, AMD will release a counterpart to DLSS 3 for RDNA 3 graphics cards, in which the AI accelerators on the gpu will be used to generate frames and display between rendered frames.

In the area of ​​software, AMD also plans to introduce Hypr-RX in the first half of 2023. This function should make it easier for gamers to choose an optimal game profile in the Adrenalin software, without having to manually select features such as Boost, FSR and SuperResolution.

Expected Performance

In the presentation, AMD makes a number of performance claims for the RX 7900 XTX, but the manufacturer does not make a direct comparison with Nvidia’s GeForce RTX 4090. Overall, up to 50 percent better ray tracing performance is promised than on the RX 6950 XT, and in rasterization this would be between 4k. the 50 and 70 percent should be. If AMD can make this happen, it will be a matter of game whether the RTX 4090 or the RX 7900 XTX is faster. It is also striking that AMD seems to suggest in its presentation that FSR on RDNA 3 provides a greater performance increase than is the case proportionally on the RX 6950 XT.

Prices and availability

The AMD Radeon RX 7900 XT and RX 7900 XTX will be available from December 13, according to the manufacturer in both reference versions and custom cards that the board partners will come with. The suggested retail price of the RX 7900 XT is USD 899, the RX 7900 XTX will have a suggested retail price of USD 999. Converted to euros, with the current exchange rate including VAT, that is currently 1110 euros for the RX 7900 XT and 1233 euros for the RX 7900 XTX.

RX 7900 XTX RX 7900 XT RX 6950 XT