In a letter to investors, Google co-founder Sergey Brin said that demand for the powerful computers used to mine ether and other cryptocurrencies has contributed to a “boom of computing.”

Brin wrote Saturday that several factors have led to a surge in computing power that has seen search giant Google’s own processors speed up by a factor of 200,000 over a period of 20 years. The first factor is the “steady hum of Moore’s Law,” referring to the observation that computing power per square inch of a chip tends to double every other year.

The second factor is increased demand for processing heft, partly from gamers and their graphics-hungry rigs but also “surprisingly, from the GPU-friendly proof-of-work algorithms found in some of today’s leading cryptocurrencies, such as Ethereum.”

GPUs, or graphics processing units, are used to “mine” ether: to update the cryptocurrency’s blockchain through a process known as proof of work, which involves rapidly crunching through cryptographic functions. (Ethereum miners may not use GPUs for much longer, however, given that a specialized piece of hardware has been developed by Bitmain)

Brin did not feel either of these factors was the biggest contributor to the computing “boom,” however. That factor, he wrote, is machine learning, a data-intensive technique used to develop artificial intelligence systems that can drive cars, recognize faces or translate texts without human input.

Google has explored uses for blockchain technology, the cryptographic structures that underpin cryptocurrencies such as bitcoin and ethereum, but has made very little mention of cryptocurrencies themselves – except to ban browser extensions for mining and ads for initial coin offerings.

Sergey Brin image via Wikimedia.