AMD has finally announced its next-generation GPU architecture, RDNA 3, and the first two cards based on this architecture, the Radeon RX 7900 XTX and Radeon RX 7900 XT. Both cards will be available for purchase on December 13, 2022.

We have been waiting a long time for details on these two cards; the RX 7900 XTX promises up to 61TFLOPS of computing performance, about three times the 23TFLOPS of the RX 6950 XT.

The RX 7900 XTX employs the power of 96 RDNA 3 compute units (CUs), approaching triple digit numbers. It runs at a game clock of 2.3GHz and has a total of 24GB of GDDR6 VRAM. As the top card announced by AMD today, this has a total board power (TBP) of 335W. This is the same TBP as the RX 6960 XT, but the RX 7900 XTX promises to be up to 67% faster than the card it replaces at the top of the line.

The RX 7900 XTX is priced at $999.

Next, there is the RX 7900 XT. This has 12 CUs less than the XTX model, for a total of 84 CUs. It has a gaming clock of 2 GHz and 20 GB of GDDR6. the TBP is somewhat modest at 300W.

The RX 7900 XT is only $100 less than the RX 7900 XTX at $899, so if you can get it for $999, you may want to look at the more powerful card; if you don't care about VRAM capacity, the RX 7900 XT may be the smarter buy, but the final The decision will come down to the performance difference between the two.

AMD has provided some graphs to whet gamers' appetites ahead of the launch.

However, AMD has not ruled out partners adding another 8-pin for even more power on overclocked cards.

DisplayPort 2.1 is also supported via AMD's new Radiance Display engine, which allows frame rates of up to 480 Hz at 4K and 165 Hz at 8K. Whether you can actually take full advantage of this is another story entirely, but it is good to see AMD include a display connector that Nvidia did not make prominent with the RTX 4090 (opens in new tab).

The GPU is where things get interesting; AMD is packing 58 billion transistors into its new GPU, but not all of them are in one place. These are chiplet-based gaming GPUs, which, as AMD eagerly adds, are a world first.

Taking some of what it learned from the chiplet-based Ryzen CPUs, AMD has included two new core components in the RDNA 3 GPUs: the GCN and the MCN.

The actual rendering core, which handles floating-point and integer operations, is located in what is called the GCN. the RX 7900 XTX and RX 7900 XT each have a single GCN of 300 mm2. the GCN is built on TSMC's 5nm process node. and includes the hardware needed for AI, rendering, and ray tracing, as well as the media and display engines.

GCN also offers full support for AV1 encoding and decoding, AVC, and HEVC; AI acceleration is also significantly improved, up to 2.7x over the previous generation. But if you are only looking for gaming performance, don't worry. The new GCNs have improved ray tracing capabilities, delivering up to 50% more performance per CU, and looking at the graphs provided by AMD, this appears to make a big difference in the playability of games with ray tracing enabled on RDNA 3. These are much smaller chips than GCNs, measuring 37mm2 apiece. They are manufactured on TSMC's 6nm process node. They each have a 64-bit memory controller and a second-generation Infinity cache. [In the RX 7900 XTX, all six of these MCNs are functional. On the RX 7900 XT, on the other hand, only five of them actually function. According to AMD, the sixth chip will still be present, but this is due to manufacturing reasons, presumably for the packaging process and also for optimal cooling.

This means that the 7900 XTX will have a 96 MB Infinity Cache and the 7900 XT will have an 80 MB Infinity Cache. AMD did not state these specifications for either card during the event, so other We have to infer this from other comments about the MCN design.

RDNA 3 uses split clocking in the shaders and front end. According to the company's engineers, gaming performance was limited more by the front end than by the actual shaders themselves; RDNA 3 splits the shader clock and front end clock to speed up the front end up to 2.5 GHz and slow down the shader clock to 2.3 According to AMD, this is effectively a 15% increase in frequency while maintaining 25% power savings.

We don't know how this split clock will affect overclocking when you actually get these cards, but AMD believes there will be some headroom for overclocking, both from card partners and from home gamers.

Of course, the big question on everyone's lips before the announcement was whether AMD's RDNA 3 architecture had enough to beat out Nvidia's recently released RTX 4090. We didn't hear much about that comparison during the live stream; if you're thinking it's because the RX 7900 XT can't match the RTX 4090 in gaming, you may be right.

During the post-stream Q&A, AMD hinted that they don't necessarily intend to compete with the RTX 4090. We are competing for under $1,000," said Scott Herkelman, AMD's Radeon GM. He added that he believes in "what we are offering in terms of performance and price."

We won't have to wait too long to see how strong these cards will be in the game; both the RX 7900 XTX and RX 7900 XT will be available for purchase on December 13, and AMD's partners are preparing to announce their own designs for both cards on the same day.