AMD’s RX 6700 XT is slower at mining than its predecessor – Here’s why

AMD's RX 6700 XT is slower at mining than its predecessor - Here's why

AMD’s RX 6700 XT is slower at Ethereum mining than its predecessor – Here’s why

AMD’s RDNA 2 architecture is built for gaming, not cryptocurrency mining, making the architecture deeply sub-optimal when it comes to Ethereum. Yes, Radeon graphics cards remain profitable, but there is a reason why AMD’s ageing Radeon VII can outperform anything within AMD’s current-generation product stack. 

Thanks to the Crypto Mining Blog (via Videocardz), we now know the Ethereum mining hash rates of AMD’s Radeon RX 6700 XT, and its a lot lower than its last-generation counterpart, the Radeon RX 5700 XT. 

According to the Crypto Mining Blog, AMD’s Radeon RX 6700 XT offers a hash rate o around 43.5 MH/s, which is much lower than the 54.75 MH/s hash rates that the RX 5700 XT can offer. No, AMD has not throttled the performance o their RX 6700 XT; they’ve just designed it with gaming in mind, not mining. 

AMD's RX 6700 XT is slower at mining than its predecessor - Here's why

Ethereum mining is limited by memory bandwidth

Mining Ethereum requires a lot of memory bandwidth and will max out any modern graphics card’s memory performance. After a certain point, adding more compute into the mix will not improve your mining performance, which is why most cryptocurrency miners overclock their VRAM and lower their GPU core clock speeds to enable peak performance and maximised efficiency within their systems. 

With this in mind, it is easy to see why AMD’s top-performing mining graphics card is the Radeon VII, as it offers over 1TB/s of memory bandwidth. This is also why older graphics cards like AMD’s RX Vega 64 will compete with the Radeon RX 6700 XT when cryptocurrency mining. 

Bandwidth is why Nvidia’s RTX 3080 is such a highly sought after graphics card for cryptocurrency mining on the Nvidia side, as it combines a wide 320-bit memory bus with high-speed GDDR6X memory modules. This is also why the RTX 3060 Ti and RTX 3070 offer the same mining performance, as both offer users 8GB of GDDR6 memory across a 256-bit memory bus. 

AMD’s Infinity Cache hampers Radeon’s cryptocurrency mining performance

AMD RDNA 2 architecture minimises Radeon’s need for raw memory bandwidth by adding a last-level cache to their latest graphics cards. This cache is called Radeon Infinity Cache, and it is not useful to cryptocurrency miners. 

Ethereum mining workloads are too large to benefit much from AMD’s Infinity Cache, which is why Ethereum mining is most profitable on graphics cards with fast memory and a wide memory bus. AMD’s RDNA 2 allows Radeon to achieve high levels of gaming performance without an ultra-wide memory bus’, making it an architecture designed for gamers, not miners. 

If AMD wants to make an ultra-fast mining graphics card, all they need is a re-release of their Radeon VII with faster HBM2 memory modules. As it stands, RDNA 2 is deeply sub-optimal for mining, and that is a good thing for gamers. 

AMD's RX 6700 XT is slower at mining than its predecessor - Here's why  

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