Despite the bearish cryptocurrency market in 2018 following the explosive bull run of 2017, the computational power behind SHA-256 coins has continued to grow exponentially. Bitcoin (BTC) and Bitcoin Cash (BCH) have together created one of the largest computational networks in human history, now firmly in the Exahash era (10^18 hashes per second). This achievement is a testament to the resilience of decentralized mining and the engineering marvel of Nakamoto consensus.
From Petaflop to Exahash: A Leap Ahead of Expectations
In May 2013, the Bitcoin network's hashrate surpassed 1 Exahash, making it six to eight times faster than the combined speed of the top 500 supercomputers at the time. By May 2018, Bitcoin's hashrate had reached 30–35 Exahashes per second (EH/s), while Bitcoin Cash stood at 3–5 EH/s. Together, they account for more than two-thirds of all SHA-256 hashrate across every coin.
Interestingly, computer scientists had predicted that exascale computing (one exaflop per second) would be achieved by 2018, coinciding with the launch of the IBM Roadrunner supercomputer in 2009, which first broke the petaflop barrier. However, the Bitcoin network crossed 1 Exahash in 2016 — two years ahead of the prediction — and BCH followed in late 2017. This early realization of exascale computing was driven entirely by voluntary mining activity, not by government-funded research or corporate supercomputing projects.
A Decentralized Marvel: No Central Authority Required
Unlike traditional high-performance computing clusters managed by governments or technology giants, SHA-256 mining networks operate without any central control. Miners around the world voluntarily deploy ASIC hardware to process blocks and earn rewards. The profit motive alone has driven hashrate to record-breaking levels, proving that decentralized incentive structures can rival — and even exceed — the capabilities of centralized supercomputing.
The trend is expected to accelerate. Later in 2018, new mining rigs featuring 10nm and 7nm chips will enter the market, likely pushing hashrate even higher. Some analysts project that if SHA-256 networks surpass 500 Exahashes per second, they will enter the Zetahash era. Despite the market downturn, miners continue to invest in infrastructure, confident in the long-term value proposition of these decentralized networks.
Engineering Milestone: The Exahash Legacy
The Exahash era marks a significant milestone in computer engineering. In 2009, the IBM Roadrunner supercomputer achieved a petaflop, a moment celebrated as a breakthrough in scientific computing. Less than a decade later, a decentralized cryptocurrency network has achieved processing power orders of magnitude greater — without a single central command center. This demonstrates that Nakamoto consensus can mobilize global computational resources more efficiently than traditional top-down models.
Love them or hate them, miners have formed a symbiotic relationship with the underlying technology, pushing the boundaries of what is computationally possible. The fact that this has been accomplished without any government or corporate backing is nothing short of extraordinary. As Bitcoin and Bitcoin Cash continue to break records month after month, the Exahash era stands as a powerful reminder of the potential of decentralized technology to reshape the world's computing landscape.