Zcash NU7 Is Live and Our Solo Pool Is Already Mining It

We watched the height counter tick down on our Zcash node this morning. Block 3,543,405 came in, the node logged the switch to NU7, and the next job went out to our miners with the new rules. No restart, no scramble. That's the upgrade you want: boring.

Here's what changed, what we run, and what it means if you point Equihash hardware at our Zcash solo pool.

What NU7 changes for miners

The big one is block time. Zcash used to target a block every 75 seconds. From NU7 it targets one every 25 seconds, so the chain goes from about 1,152 blocks a day to about 3,456.

The miner subsidy was cut to match. Before NU7 the miner got 1.25 ZEC per block. Now it's about 0.4167 ZEC, a third of the old amount, which is what Zebra's getblocksubsidy reports for NU7 heights. Three times the blocks at a third of the size means the ZEC issued per hour stays the same. Fees in the block still come on top.

For a solo miner that's a real change in how luck feels. Say your rig's odds worked out to one block a month before. Now it's roughly one block every ten days, each worth a third as much. Same expected ZEC over time, but fewer long dry spells. Solo is still a lottery, just with more draws.

One honest downside: jobs now change three times as often. If your miner sits on a slow link, more of your shares will land on stale work. Pick the endpoint with the lowest ping and keep an eye on your reject rate for the first day.

Our node: Zebra 7.0.0

The pool gets its block templates from our own Zebra node, a Linux box on the same LAN as the pool server. It runs Zebra 7.0.0, the stable release that activates NU7 on mainnet and speaks network protocol 170190. Older Zebra and zcashd builds stop following the chain at the NU7 height, so if you run your own node, check its version today.

The 7.0.0 notes have a few fixes that matter for a pool more than for a wallet:

• Mined-block broadcasts no longer stall when peers drop or reconnect in waves.
• The block gossip task doesn't stall when no peers are ready. Before, that could make submitblock return an error for a block that had actually been accepted.
• Shorter sync stalls near the chain tip. With 25-second blocks, a few seconds behind the tip costs more than it used to.

7.0.0 also has a shorter support window than usual: 8 weeks instead of 12. Our node reports end of support at block 3,684,728, around mid-December, so we'll move to the next stable release well before that.

There's also a 7.1.0 alpha out with faster template rebuilds and quicker work on a new tip. Those are exactly the things a pool wants with 25-second blocks. But it's an alpha, the Zebra team says to run it on a test node, and we don't test on the node that builds your coinbase. We'll switch when it ships as stable.

How our Zcash solo pool works

• Fee: 2% of the block reward, only when your address finds a block. No signup, no account, no withdrawal minimum.
• Payout: if you mine to a transparent address (t1, t3 or tex1), the block's coinbase pays you directly. 98% of the miner reward goes to your address on-chain, spendable after 100 confirmations. We never hold your coins.
• Stratum: stratum+tcp://zec.mysolopool.com:3330 with vardiff for ASICs and GPUs. Port 3331 has a fixed difficulty for NiceHash and other rentals.
• Username: your Zcash address, plus a worker name if you like.

Before NU7 we also re-checked the split coinbase against the node. The pool test-builds a block with the 2% / 98% split and asks Zebra to validate it at startup and every 15 minutes. If a check ever fails, the pool falls back to the normal coinbase instead of risking an invalid block.

Dashboard, live hashrate and found blocks are at zcash.mysolopool.com.

Our other solo pools

Same idea on every coin: your wallet address is your username, and the pool connects straight to our own full nodes.

• Bitcoin (BTC): mysolopool.com, stratum btc.mysolopool.com:3334. 2% only when your address finds a block. Works with Antminers, Whatsminers and Bitaxe.
• Bitcoin Cash (BCH): bitcoincash.mysolopool.com, stratum bch.mysolopool.com:3334. Also 2%. A separate SHA-256 lottery with much lower difficulty than Bitcoin.
• Litecoin + Dogecoin (LTC + DOGE): doge.mysolopool.com, stratum scrypt.mysolopool.com:3341. Merged Scrypt mining, so one L7 or L9 hunts LTC and DOGE blocks at the same time. Fee details are on the pool page.

All the nodes behind these pools run current releases on our own hardware. If something on a dashboard looks off, message us. A person reads it.

Not sure which coin suits your hardware? The solo pool page lists all four side by side.