A new leak of AMD's upcoming Radeon RX 6000 series (including Big Navi graphics cards) has appeared in Apple's macOS BigSur 11 beta. From the looks of it, AMD's new cards could boast promising performance to challenge the Nvidia GeForce RTX 3080.

A Reddit user posted specs for both Big Navi (aka Navi 21) and Navi 22 (codenamed Navy Flounder). The specs contain much of the information leaked in the recent Linux update, this time revealing tidbits about clock speeds.

The latest leaks indicate that Big Navi will have 80 compute units (CUs) and 5,120 stream processors, and newer leaks indicate that one version of Big Navi will have up to 2.2 GHz clock speeds. Comparatively, the regular version of the GeForce RTX 3080 boosts to 1.71 GHz.

Our sister site Tom's Hardware also points out that the Navi 21 can deliver 22.5 Tflops of single precision performance. While this is an impressive number, it falls short of the GeForce RTX 3080's 29.8Tflops. In other words, Big Navi may not be the "Nvidia killer" that has been favored for some time. [Interestingly, the clock speed of the Navi 22 is said to reach 2.5Ghz. However, it is said to have 2,560 stream processors and 40 CUs. This means that it will deliver 12.8 Tflops of performance.

Both graphics cards appear to offer a more powerful upgrade over the Radeon RX 5700 XT and RX 5700, which are based on the older RDNA architecture; the Radeon RX 6000 series also features PS5 and Xbox Series X GPUs AMD's RDNA 2 architecture.

Tom's Hardware also mentions the Navi 31, which may have the same stream processors and CUs as the Big Navi, but with higher clock speeds and increased performance. Most notably, however, it will feature AMD's RDNA 3 GPU architecture, which could be a future refresh of Big Navi.

It should be noted that Mac machines tend to use Radeon Pro graphics cards, so the clock speeds and teraflops performance may not be correct for a consumer product that can be installed in a gaming PC.

The Radeon RX 6000 series is scheduled to be announced on October 28. Therefore, we do not have to wait very long to see what AMD has in store for the next generation of graphics cards.