Cryptomining
Aside from gaming and creative applications, there’s one other role to which graphics cards are uniquely well suited: cryptomining, the process by which individuals can generate bitcoins and other cryptocurrencies.
The reason why graphics cards are so good at this job isn’t hard to understand. To earn bitcoins, you need to solve a complex “hashing” problem. There’s no known way to do this quickly: you just have to guess a number, apply a mathematical transformation and see if the right answer comes out. The difficulty level goes up and down depending on how quickly the last answer was found; at the time of writing, it was at around 25,000,000,000,000, meaning each guess has a chance of approximately one in 25 trillion of being correct.
If you’re using a CPU to do your hashing, you can try a lot of numbers pretty quickly: the 24-core Intel Core i9-10920X can test more than 5,320 hashes per second. But that’s nothing compared to a top-of the range graphics card. The GeForce RTX 3090, with more than 10,000 CUDA cores, can rip through 120,000,000 hashes every second. If you leave it running then, at current market rates, it should earn you around £6 per day in bitcoins, or more if you’re canny about speculating in other cryptocurrencies. That might not seem like an amazing return on investment, and it’s not great for the environment. But the competitive edge has seen crypto-enthusiasts snapping up recent RTX cards, resulting in a months-long stock shortage and sky-high prices on the secondhand market. The RRP of the GeForce 3090 RTX is already decidedly steep at £1,399, but if you want to buy one today your only option might be to go to eBay and pay double.
In a bid to calm the situation down, Nvidia announced in February that it was introducing “hash-limiting” firmware to various RTX models, which deliberately slows down cryptocurrency hashing functions without affecting other operations. It’s probably the only instance in history of a graphics company taking steps to deliberately diminish the power of GPU computing – though to compensate, the company has launched a separate CMP range of cards designed specifically for mining.