Gemini has deployed Zakura, a new Zcash node client replacing its Zebra software, ahead of the network's NU7 upgrade scheduled for Nov. 5.
The Zakura deployment synchronized with the latest Zcash block in just over six hours—a 75 percent reduction from Zebra's typical near-24-hour sync window. Independent testing by Zakura developers showed even faster performance: four hours and 20 minutes under identical conditions, compared to nearly 21 hours for Zebra.
The upgrade matters because NU7 reduces Zcash block times from 75 seconds to 25 seconds, forcing network nodes to process and validate transactions at triple the current rate. Any exchange running outdated or slow-syncing infrastructure risks deposit and withdrawal halts during the transition. Gemini's move eliminates that risk window.
Zakura also offers snapshot sync—downloading a recent copy of network data rather than rebuilding the entire transaction history from genesis. Testing showed this approach 680 times faster than standard synchronization, critical insurance for node operators managing custody of customer deposits.
The Winklevoss brothers have deeper skin in the game than most exchanges. Their investment firm led a $59 million financing round for Cypherpunk Technologies, which holds and mines ZEC. A Winklevoss affiliate sold a Zcash mining fleet to Cypherpunk for $33 million in August. Gemini manages custody and trading of Cypherpunk's ZEC holdings.
Before NU7 activates on mainnet Nov. 5, Zcash developers will run a testnet phase starting Oct. 6 to assess performance under accelerated block production. Gemini has not yet published performance benchmarks for Zakura under the faster NU7 block schedule.
