Ladies and gentlemen, we now match Visa scalability.

On Friday, Bitcoin Unlimited (BU) chief scientist Peter Rizun announced on Twitter that the “world’s first 1.0001GB block has been mined and propagated on the Gigablock Testnet,” proving that big blocks are really the way to go.

Gigablock Testnet, also known as BUIP065, is the project backed by BU, blockchain technology research and development outfit nChain and the University of British Columbia that seeks to determine how large blocks Bitcoin can handle as well as identify the bottlenecks that may obstruct the network’s scalability, which currently pales in comparison to Visa’s throughput. Increasing the network’s block size limit from 1MB is needed to reduce fees and make confirmation times reliable again. Bitcoin Cash has already shown that lower fees are acceptable, although confirmation times can still be skewed due to the current network situation.

The initiative has outlined four objectives, including the set-up and maintenance of a global test network capable of supporting up to 1GB blocks and sustained Visa-level transaction throughput (3,000 TPS) on the Bitcoin network.

After receiving the approval from BU members in late September, the project put up mining nodes in Toronto, Frankfurt, Munich, Stockholm, and central Washington State. Additional mining nodes are scheduled to be deployed in Beijing, Bangalore, Sao Paulo, Sydney and Vancouver, according to BU.

Preliminary results

When asked what was the group’s preliminary findings, Rizun said they found that transaction admission into mempool was the biggest bottleneck. Specifically, the single-threaded nature of the present design of admitting transactions into mempool appeared to be the dominant bottleneck, the team stated in their Scaling Bitcoin Stanford presentation proposal.

“When I created the 1GB block yesterday (Thursday), it was to show technical feasibility (to prove the SW can HW can handle it),” BU lead developer Andrew Stone wrote on reddit.

The BU team said they are currently performing “a series of ‘ramps,’ where the transaction generators were programmed to increase their generation rate following an exponential curve starting at 1 tx/sec and concluding at 1000 tx/sec… to identify bottlenecks and measure performance statistics.”

“We are not going from 1MB to 1GB tomorrow. The purpose of going so high is to prove that it can be done—no 2nd layer is necessary. By the time we get blocks even over 10MB we’ll have technologies like utxo commitments and partial syncing clients (imagine a node that behaves as a SPV client upon startup, but is transitioning to a full node in the background) which will make your UX much better,” Stone added.

Scaling improvements realized through the Gigablock Testnet Initiative are expected to be implemented first on Bitcoin Cash, according to Bitcoin Unlimited. Previously, nChain has been able to test 32MB blocks and BU’s “nolnet” testing network has successfully tested 64MB blocks. And now this latest breakthrough, which leaves the 1MB block looking a lot like a thing of the past.

“Bitcoin Cash is a magnificent system for doing online payments. 0-conf 200% faster than Visa in under 2 seconds at 99.8% distribution. Safer than Visa who has a 1.2% loss in some areas. Settled 6 blocks completely not 60 days. Cost of double spend $68,000 USD,” Dr. Craig Wright, chief scientist of nChain, tweeted. “Bitcoin is better than Visa and even coins.”