A vintage Bitcoin forum post from September 2010 has recently regained market attention. The post shows that, during a time when Bitcoin had virtually no market price, early users were already carefully calculating the electricity costs of mining with home computers and debating whether it was worthwhile.
The electricity cost for a single block is approximately $5.68.
The user TTBit measured the computer's power consumption using a power meter and found that, after turning off the monitor, the total power draw was approximately 140 watts. According to their calculation, this computer has a hashing power of about 2,200 kilohashes per second.
Considering the network difficulty at the time, TTBit estimates that mining one block would take approximately 14 days and 2 hours, consuming about 47.3 kilowatt-hours of electricity. At a rate of $0.12 per kilowatt-hour, the electricity cost would be approximately $5.68.
At the time, the Bitcoin block reward was 50 BTC, yet this user still referred to the scheme as "losing money." This reflects that in 2010, Bitcoin had not yet achieved its current market value, and miners' expectations of returns were vastly different from today.
The forum has begun discussing GPU mining.
This post also documents the early stage of Bitcoin mining's transition from CPUs to GPUs. TTBit noted that users employing CUDA software with graphics cards achieved a hash rate of 25,000 kilohashes per second, significantly higher than that of standard CPUs.
Another participant noted that an Nvidia GTX 260 graphics card could achieve 33 kilohashes per second at a power consumption of approximately 200 watts—a level of efficiency far surpassing that of consumer CPUs, making GPU mining economically viable.
At the time, TTBit assessed that GPU mining could become profitable again if the total power consumption of graphics card equipment could be kept below approximately 1,000 watts.
Satoshi Nakamoto also participated in the discussion.
This post also attracted the participation of Satoshi Nakamoto, the creator of Bitcoin. In the post, Satoshi estimated that a 24-core AMD system could achieve approximately 66 kilohashes per second.
TTBit also attempted to estimate the network difficulty at the end of 2010, predicting it could rise to approximately 6,672. Another forum user suggested this figure might even be conservative. At the time, TTBit wrote that if this trend continued, generating new coins would become considerably difficult in the future.
Looking back, this assessment proved largely correct. As difficulty continued to rise, GPUs became widespread, and ASIC miners subsequently emerged, Bitcoin mining quickly evolved from a personal computer experiment into a highly specialized global industry.