CPU Mining

CPU mining is mining Bitcoin using a general-purpose computer processor instead of specialized hardware. It was the only way to mine Bitcoin in 2009-2010, and it's been economically extinct on Bitcoin's mainnet for over a decade.

The historical progression:

• 2009-2010: CPU mining. Anyone with a laptop could find blocks. Satoshi and Hal Finney mined this way.
• Late 2010: GPU mining started. Graphics cards turned out to be roughly 50-100× faster at hashing than CPUs. CPU miners couldn't compete.
• 2013: ASICs arrived. GPU miners became uncompetitive in months.
• 2014+: ASIC-only era. CPU mining produces 0.000000001% of network hash rate, if that.

Why CPU mining still has a (tiny) place in culture:

• Educational value. Running a CPU miner against testnet or regtest is how a lot of developers first learned what hashing actually is.
• Lottery hardware. A handful of people have famously won mainnet blocks solo-mining on cheap hardware over the years - a USB-stick miner, a home GPU, occasionally a CPU. The probability is astronomical against, but the lottery aspect appeals to some hobbyists.
• Some altcoins still favor CPU mining (e.g., Monero's RandomX). The economics there are different. On Bitcoin specifically, CPU mining is purely sentimental.

If you ran a CPU at 100% on Bitcoin's mainnet for a year, your expected block discoveries would be a number with many zeros after the decimal point. You'd likely heat your office, scare your electricity provider, and never find a block. The math of hash rate doesn't favor amateurs.

See Mining Rig for what does work in 2026.