An analysis said that if a mining pool keeps its existing high difficulty after the hashrate of Bitcoin mining rigs drops sharply, miners may continue consuming electricity while failing to submit the shares needed to calculate rewards.

Cryptoslate, a blockchain media outlet, reported on Sunday local time that the issue is tied to how variable difficulty (Vardiff) controllers automatically adjust the share difficulty assigned by mining pools to each connection, rather than the overall mining difficulty of the Bitcoin network.

The issue drew attention after Bitcoin Optech revisited the possibility of controller malfunctions based on analysis by mining engineer Eric Price. The analysis presented potential weaknesses and verification methods, but it did not prove large-scale losses across the mining industry.

Mining pools assign each miner a share difficulty far lower than the difficulty required to create a Bitcoin block. They use assigned shares to estimate hashrate and settle contributed work. A variable difficulty controller adjusts settings so that shares are submitted at an appropriate frequency.

The problem arises when a miner’s computing power suddenly drops. If difficulty is recalculated only when a new share arrives, the high difficulty set before the slowdown can remain in place. Equipment with reduced computing power takes longer to find shares that meet the existing difficulty, and the longer share submissions are delayed, the longer difficulty adjustment is also delayed.

In that case, miners keep performing hash computations and consuming power, but submit shares approved by the pool only very rarely. Even if the equipment keeps running, proof of work needed for reward settlement does not accumulate in time.

Under the current Stratum V2 mining standard, difficulty is recalculated periodically using a timer. If share submissions become infrequent, the system lowers difficulty to avoid a situation in which submissions remain blocked. Channels that have been maintained for a long time may recover more slowly.

As an operating example, ckpool was cited as adjusting difficulty based on share submissions. However, how widely this method is used and whether it has caused meaningful losses cannot be confirmed from currently available public information.

The key question is how quickly a mining pool can adjust share difficulty when a miner’s computing power drops sharply. It is necessary to check whether recovery mechanisms that lower difficulty work in practice even when share submissions stop.