Bitcoin Knots plans a test of a BLAKE2b proof‑of‑work fork of Bitcoin on Sunday, after its earlier chain split stalled after two blocks.

The proposal aims to replace Bitcoin’s SHA‑256d proof‑of‑work with BLAKE2b and to shift the breakaway network to hardware designed for Sia mining, including Bitmain Antminer A3 and Goldshell SC5 models.

Developer Luke Dashjr instructed SHA‑256d miners to pause mining before an August 30 test that would activate the new proof‑of‑work algorithm. The test will use Bitcoin Knots version 29.4.1rc4 to create the final SHA‑256d block before the switch. If the rehearsal proceeds, a final 29.4.1 release could preserve the chain on September 1.

A code review estimates that maintaining 10‑minute block intervals would require roughly 870 terahashes per second, far exceeding the 50 to 70 terahashes estimated for testnet4 capacity. Compatible mining machines do not guarantee committed hash rate, and the amount of hash power pledged by operators remains undisclosed.

The fork changes the block header from 80 bytes to 164 bytes, requiring updates to light wallets, indexers, explorers and other infrastructure. Bitcoin Knots says light‑client compatibility is outside its scope, and exchanges have been advised to pause deposits and withdrawals around the split.

Even if miners produce blocks under the new rules, the broader test involves whether exchanges, wallets, custodians and users will recognize sufficient economic value to sustain the chain. Lightning channels would exist on both chains, creating replay risk unless directional protection is applied.

The test will clarify activation height, block‑weight limits and other parameters, but it does not resolve whether the new ledger can achieve lasting economic viability.