Bitcoin Cash (BCH) Developer: Variable Block Size Impossible at This Point
Bitcoin Cash (BCH) has stopped at a 32 MB block size, as for now the idea of variable block size is too complex. BCH ABC developer Amaury Secher, or “deadalnix”, has explained the challenge in a recent Reddit thread.
A user suggested the BCH network could start producing blocks with 512 MB to store transactions, thus potentially allowing up to 2,000 transactions per second. This would match VISA-level activity. However, a block of this size is still hypothetical and can seriously challenge the network.
The suggestion leads the Bitcoin
Cash project down the line of Bitcoin SV, which is attempting extreme block sizes to scale on-chain. However, the BSV approach will also change the nature of miners, turning them into known entities with a heightened investment in resources.
For a network of multiple voluntary nodes, propagating a 512 MB block would be impossible.
“The bigger the block, the higher the chance of being orphaned. So the making a block that does not propagate means a miner loses the revenue.
Inherently the system has a technical limit. No one dictates it. It's discovered by accident when your block is orphaned because it is too large,” explained one user.
The matter of large blocks is also hypothetical and depends on the growth of available technology. Currently, the Bitcoin Cash network only carries about 42,000 transactions per day, not even close to a demand for 2,000 transactions per second.
Currently, most networks don’t go near the limit for the largest blocks that can propagate. But the push to large blocks may mean further network centralization. Only dedicated miners would be capable of propagating the block.
The Bitcoin Cash network has 1,525 nodes, and may be too large to propagate those large blocks. Miners would have more incentives to carry light blocks, while requiring higher fees in case of network congestion. Otherwise, they would only get low fees, along with the requirement to carry high-capacity hardware.