Bitcoin Cash 1-minute blocks face a November 15 lock-in: what changes for miners

Bitcoin Cash is heading into a decision week. The proposal to cut its target block time from 10 minutes to 1 minute, CHIP-2025-03 Faster Blocks, is up for lock-in on 15 November 2026, the date it is set to activate on the chipnet test network at 12:00 UTC. If it is locked in, the mainnet switch is planned for 15 May 2027 at 12:00 UTC, measured by median time past.

What changes for SHA-256 miners

Blocks would come ten times as often, while the reward, the difficulty and the size limit of each block drop to one tenth. The CHIP's own summary is that coin issuance per hour, the 21 million supply and the halving dates stay the same. For a miner on the SHA-256 algorithm, expected BCH income per hour of hashing does not change by design. What changes is the rhythm: smaller rewards arrive more often, which the authors say should cut payout variance for small pools.

• Block size limit: 32 MB per block today, 3.2 MB per block after the switch, the same bytes per minute.
• Coinbase maturity is redefined as 1,000 one-minute blocks, so newly mined coins wait about as long in clock time as now.
• Modeled orphan rate: 0.41% to 1.94%, under the CHIP's 2% tolerance.
• If hashrate fell to 10% of normal, blocks would slow to about 10 minutes instead of about 100.

How the test network behaved

A temporary test network with 1-minute blocks has run since 15 October. An independent count of its first 7,572 blocks, posted on Bitcoin Cash Research, found a mean interval of 67.07 seconds and a median of 43 seconds. The same post warns that many of those blocks were mined at minimum difficulty on a network with few miners, so difficulty behaviour after hashrate jumps cannot be judged yet.

Support and dissent

Test implementations exist for two node programs, Bitcoin Cash Node and Knuth. On 4 November General Protocols, which had abstained in September, formally approved lock-in this year and activation in 2027. Critics remain: in September Bitcoin Cash Node lead developer Calin Culianu said he disapproved for now because the code was not ready, and Flowee developer Tom Zander says the change breaks the way his wallet syncs. The CHIP author is still collecting statements from exchanges and other stakeholders.

What to do

Nothing changes on mainnet before May 2027, so ASICs need no action now. Pool operators and solo miners who run their own node should follow the node releases after 15 November and plan an upgrade before activation. Payout scripts and deposit rules that count confirmations will need review, because ten 1-minute confirmations carry the work of one 10-minute block. Zcash took the same path this month when NU7 moved it to 25-second blocks.