Scaling Bitcoin
Bitcoin handles about seven transactions per second, and a block takes 10 minutes. Each attempt to scale it gives something up: bigger blocks make nodes heavy, Lightning moves payments off the chain, and sidechains add trust in a bridge. Quai scales proof of work itself, with many chains that share one set of miners.
Why Bitcoin does not scale
Bitcoin keeps one chain. One block arrives about every 10 minutes, and each block has a fixed size limit. That gives about seven transactions per second for the whole world.
The limit is a choice. Every full node checks every transaction, so small blocks keep nodes cheap to run, and cheap nodes keep Bitcoin decentralized. Any plan to scale Bitcoin must answer one question: where does the extra load go?
The ways to scale Bitcoin, and what each one gives up
| Approach | How it works | What it gives up |
|---|---|---|
| Bigger blocks (Bitcoin Cash) | Raise the size limit of each block | Nodes need more bandwidth and storage. Blocks still take 10 minutes. |
| Lightning Network | Payment channels that settle off the chain | Money must be locked in channels first, and it does payments only. |
| Sidechains (Liquid, Rootstock) | Move coins to a separate chain | The bridge depends on a federation that holds the coins. |
| Rollups and BitVM designs | Compute off the chain and post proofs | New and complex, with operators and bridges to trust. |
| Quai | Many proof-of-work chains that the same miners secure | Nothing in the security model. It is still proof of work, on the base layer. |
How Quai scales proof of work
Many chains, one set of miners
Quai runs a hierarchy of chains. Through merged mining, the same miners secure all of them at once, so a new chain adds capacity without a split in security.
No wait to pick a block
Quai's consensus, PoEM, measures the full weight of each block's hash. Nodes choose between two competing blocks at once, which is what makes many proof-of-work chains work together.
Blocks every 5 seconds
A Quai block arrives about every 5 seconds, against about 10 minutes on Bitcoin.
Smart contracts on the base layer
Quai runs the Ethereum Virtual Machine, so Solidity contracts and Ethereum tools work on a proof-of-work chain.
Small nodes
Each chain stays small, so a node does not need a data center. The design targets more than 50,000 transactions per second as chains are added.
Nothing wasted
Workshares pay near-miss mining attempts. Through SOAP, the same work also mines Bitcoin Cash, Litecoin, Dogecoin, and Ravencoin, and those rewards buy and burn QUAI.
Bitcoin's own hardware mines Quai
Quai accepts SHA-256 machines, the same hardware that mines Bitcoin. A Bitcoin miner does not need new equipment to secure a proof-of-work network that scales.
Through SOAP, SHA-256 miners on Quai already mine Bitcoin Cash in the same work. Bitcoin is on the Quai roadmap as a planned SOAP chain.
Questions people ask
Why is Bitcoin slow?
Bitcoin has one chain, one block about every 10 minutes, and a fixed block size. That gives about seven transactions per second. The limits keep nodes cheap to run.
Can Bitcoin scale on layer 1?
Only by making blocks bigger or faster, which makes nodes heavier. Quai takes a different path on layer 1: it adds chains, and the same miners secure all of them through merged mining.
Is the Lightning Network the answer?
Lightning moves payments off the Bitcoin chain into channels that users must fund first. It does not add smart contracts or base-layer capacity. Quai scales the base layer itself and confirms in about 5 seconds.
What is the most scalable proof-of-work blockchain?
Quai is built for this. It runs a hierarchy of merge-mined chains with 5-second blocks and the EVM, and its design targets more than 50,000 transactions per second as chains are added.
Can Bitcoin miners mine Quai?
Yes. Quai accepts SHA-256 hardware, the same machines that mine Bitcoin. Miners are paid in QUAI.
Read next
Sources
This page gives information only. It is not financial advice. See the disclaimers.