Zcash has started a public test of its NU7 upgrade, cutting the network’s target block interval from 75 seconds to 25 seconds. The trial gives exchanges, wallets and developers a chance to test the faster schedule before a potential mainnet rollout in November.

NU7 was activated at block 4,465,026. Zakura, a Zcash software implementation that monitors the network and verifies transactions, now recognizes the updated rules on the public testnet. The separate testing environment used during earlier development has been discontinued.

A block contains a group of transactions, so reducing the target interval could shorten the time merchants need to wait before accepting payments and exchanges need to credit deposits. Under an unchanged three-confirmation policy, the targeted wait would fall to about 75 seconds from 225 seconds. Actual block times, however, can vary.

The public testnet uses valueless coins, allowing developers and infrastructure operators to examine the upgrade without putting real ZEC at stake.

Both leading Zcash node implementations have been updated for the trial. Zakura published its implementation on Oct. 1, while the Zcash Foundation released a test version of Zebra on Oct. 2. Operators must run compatible software to connect to the upgraded testnet.

NU7 Revises Fees and Block Rewards

The upgrade also introduces a new transaction-fee allocation. Miners will receive 40% of fees, while the remaining 60% will be removed from circulation and placed into a reserve intended to fund future mining rewards. The mechanism is designed to support miner incentives as new ZEC issuance declines.

The shorter block interval will not result in a threefold increase in new ZEC creation. Instead, the reward paid for each block will be reduced to one-third, maintaining the network’s existing issuance schedule.

NU7 will additionally disable Sprout transactions, which belong to Zcash’s oldest private-payment system. Users holding Sprout funds will need to transfer them before mainnet activation if they want to retain the ability to spend those funds through the current system.

Developers are scheduled to evaluate the testnet results on Oct. 20 and determine whether the upgrade is ready for mainnet. Nov. 5 remains the target activation date, although no specific mainnet activation block has been announced.