A Solana payment takes about six seconds to become irreversible today. Starting Wednesday, the network is aiming for 150 milliseconds, roughly 40 times faster, when its Alpenglow upgrade switches on.
If that target holds up on mainnet, a Solana transaction would settle in less time than it takes to blink. Hitting a number on a test network and hitting it in production are different things, though, and the road to this launch had some rough patches.
Votes move off the chain
Alpenglow changes how validators agree with each other. Validators are the computers that process transactions and vote on which ones are valid.
Right now, every validator writes its votes directly onto the blockchain like any other transaction. A payment isn’t locked in until enough of those votes stack up, and that takes about six seconds.
Alpenglow pulls the voting off the chain. Votes get bundled into certificates that can lock in a transaction in one or two rounds.
Six seconds sounds short until you’re trading in a fast market, where a price can move before your trade is final. It’s also why exchanges and payment apps make you wait before they treat a deposit as done. Cutting that to a fraction of a second puts Solana much closer to the feel of a card payment or a trade on a centralized exchange. Ethereum, for comparison, takes roughly 13 minutes to reach full finality.
Expect the transaction count to drop
One side effect will look alarming on dashboards. Robin Nordnes, CEO and founder of Raiku, which builds trading infrastructure on Solana, said in an email that people shouldn’t panic.
“Solana’s transaction count is going to look a lot lower this week, and people will ask if something’s wrong. It isn’t,” Nordnes said. “Most of what got counted before was validators voting, and that’s off-chain now. The trading’s all still there.”
He was also blunt about how much faster finality matters to professional traders. “For desks, faster finality is nice, but it was never the bottleneck. Being close to where the block is built still is,” Nordnes said.
Validators get a smaller bill
The cost side may matter more than the speed for the people running the network. Validators currently burn through about 2 SOL a day on vote fees. That cost doubled after Solana recently cut its slot times, the window each block gets, to about 200 milliseconds.
Alpenglow scraps vote fees. In their place is a flat entry charge called a validator admission ticket, set at 0.8 SOL per epoch, a period of about 24 hours. That works out to roughly 60% cheaper.
The timing isn’t accidental. Solana’s validator network has shrunk by nearly a third over the past year.
According to Bitwise’s latest staking report, the number of active validators fell to 659 at the end of September from 696 three months earlier, roughly 30% below a year ago. That happened even with 69% of SOL’s supply staked. Bitwise attributed the decline to operating costs.
Stake has also bunched up. Data from Solana Compass shows the minimum number of validators collectively controlling more than a third of staked SOL fell to 18 from 20 over the past year. The 10 largest validators’ share climbed to 24.5% from 22.2%.
Lower voting fees could ease the financial pressure on smaller validators. They don’t touch hardware, bandwidth or hosting expenses, which remain.
Six resets and a rollback
Testing didn’t go smoothly. Since launching in early May, the test network was wiped and restarted from scratch six times, according to a post from Galaxy Digital, one of roughly 100 validator operators on the test network. One attempt to migrate to the new system failed network-wide and had to be rolled back.
A later migration went through, which cleared the way for Wednesday. No real money was at risk during any of it, since the test network exists for exactly that kind of breakage.
The switch is set for the start of epoch 1064 on Wednesday. After a 5,000-slot transition, the change itself lands at slot 459,653,000.
