[DigitalToday reporter Hong Jin-ju] In the early days of bitcoin mining, calculations showed that even earning 50 BTC for mining a single block did not make financial sense once electricity costs were considered. What could now be worth billions of won, 50 BTC was then assessed as having less economic value than the power bill.

According to blockchain media outlet U.Today on Sept. 7 (local time), interest in the economics of early bitcoin mining is returning as a post uploaded to a bitcoin forum on Sept. 7, 2010 has recently been circulating again.

At the time, a forum user, TTBit, personally calculated the electricity and cost needed to mine one bitcoin block on a home computer. He connected a power meter called a Kill-A-Watt to the computer to measure actual consumption and confirmed it used about 140 watts with the monitor turned off.

Mining performance was about 2,200 kilohashes per second. Applying the bitcoin network difficulty at the time, he estimated it would take about 14 days and 2 hours to mine one block. Based on that, electricity use was calculated at about 47.3 kilowatt-hours. Using an electricity rate of 12 cents per kWh, he calculated it would cost about $5.68 to mine one block.

TTBit judged the result as effectively a "net loss." The block reward was 50 BTC, but bitcoin's market value at the time was effectively negligible, meaning the burden of electricity costs had to be weighed before the reward from mining.

Compared with now, the situation has changed dramatically. Back then, people debated whether it made economic sense to spend a few dollars on electricity to obtain 50 BTC, but after bitcoin's strong growth, 50 BTC has become an asset with enormous market value.

The bitcoin forum at the time also saw ongoing debate over whether mining or buying directly was more advantageous. With mining equipment offering low performance and power efficiency, questions were raised about whether simply keeping a computer running was reasonable.

In that process, the possibility of mining using graphics processing units began to be discussed in earnest. In the same thread, TTBit mentioned a case in which a graphics card using CUDA software delivered performance of about 25,000 kilohashes. He expected GPU mining could regain profitability if power consumption could be kept below about 1,000 watts.

Another user said an Nvidia GTX 260 graphics card achieved mining performance of about 33,000 kilohashes, with power consumption of about 200 watts. It was an example showing how much of a performance boost GPUs could bring in an environment then reliant on central processing units.

Bitcoin creator Satoshi Nakamoto (사토시 나카모토) also took part in the discussion. Satoshi estimated that using a 24-core AMD system could reach performance of about 66,000 kilohashes.

Concerns about rising mining difficulty were already being raised then. TTBit expected bitcoin mining difficulty could rise to about 6,672 by the end of 2010, and another user pointed out even that forecast could be conservative. TTBit also offered the view at the time that "if this trend continues, generating coins will become quite difficult in the near future."

The bitcoin mining ecosystem later moved quickly from CPUs to GPUs, FPGAs and ASICs, intensifying competition. As network participants increased and mining difficulty rose, the early mining environment centered on personal computers effectively disappeared.

In 2010, the $5.68 electricity bill mattered more than the 50 BTC block reward, but the same discussion already showed mining efficiency and network difficulty emerging as key variables that would shape bitcoin's ecosystem.