AMD Big Navi could beat RTX 3080 — here's the proof

AMD Radeon RX 6000
(Image credit: AMD)

Specs for the “Nvidia-killer” AMD Big Navi graphics card have been found in a Linux update and show how the GPU could challenge the Nvidia GeForce RTX 3080

A Reddit user spotted a listing in the new ROCm (Radeon open compute) firmware update that details two graphics cards based on AMD’s new RDNA 2 architecture, which underpin the graphics in the PS5 and Xbox Series X. The update listed the Sienna Cichlid and Navy Flounder codenames, thought to be Big Navi (Navi 21) and a Navi 22 or 23 graphics card. 

AMD has already announced that it has the Radeon RX 6000 series in the works and it's set to be revealed on October 28, meaning that we’re expecting more than one next-generation GPU from Team Red. So the pair of graphics cards in this listing isn’t too surprising, 

However, our colleagues at Tom’s Hardware noted that the most interesting tidbit here is that BIg Navi will feature 80 compute units and use a 256-bit memory bus. Through a bit of hardware number wrangling, each CU tends to work out at 64 steam processors, so 80 CUs equates to 5,120 stream processors. 

Now AMD’s Radeon stream processors can’t be compared to Nvidia’s CUDA cores, but 5,120 stream processors is a lot. And when we take into account that RDNA 2 uses a 7-nanometer process, there’s a good chance that Big Navi will be around as powerful as the RTX 3080 and more efficient; Nvidia’s Ampere architecture at the heart of the RTX 3080 is based on an 8nm process. 

AMD Big Navi is predicted to snap at the heels of the GeForce RTX 3080, and the specs in this Linux listing seem to confirm that. But Big Navi is still more than a month away. So AMD has the scope to fine-tune the performance of the graphics card, meaning we should be a little cautious at taking these numbers at face value. 

Like we’ve said before, if Big Navi can offer performance close to the RTX 3080 but at a cheaper price, it could be onto a winner given the Nvidia graphics card is very tricky to buy at the moment

As for Navy Flounder, this graphics card will sport 40 CUs and use a 192-bit memory bus. This will likely be a mid-range graphics card to replace the older Radeon RX 5700 XT and challenge the likes of the GeForce RTX 3060, which looks very likely to be on its way. 

We’ll have to wait a good few weeks before we get a proper lowdown on the next-generation AMD graphics cards. But for PC gamers keen to upgrade their GPUs, the fall will be an interesting time indeed, especially with the GeForce RTX 3070 coming in October. 

Roland Moore-Colyer

Roland Moore-Colyer a Managing Editor at Tom’s Guide with a focus on news, features and opinion articles. He often writes about gaming, phones, laptops and other bits of hardware; he’s also got an interest in cars. When not at his desk Roland can be found wandering around London, often with a look of curiosity on his face.