Today a Solana payment needs about six seconds before it can’t be reversed. The network wants to bring that down to 150 milliseconds, about 40 times faster, once the Alpenglow upgrade activates on Wednesday.
Should mainnet actually deliver that figure, Solana transactions would settle faster than a blink. Reaching a target on a test network is one thing and reaching it in production is another, and getting to this launch involved a few setbacks.
Voting leaves the chain
The upgrade rewrites how validators reach agreement. Validators are the computers that process transactions and cast votes on which ones count as valid.
Under the current design, each validator records its votes straight onto the blockchain, the same way any other transaction gets recorded. A payment only becomes locked in after enough of those votes pile up, a process that runs about six seconds.
With Alpenglow, voting happens off the chain. The votes are packaged into certificates, and those can lock in a transaction within one or two rounds.
Six seconds feels quick until you’re trading in a market that moves fast and the price shifts before your trade is final. That delay is also the reason exchanges and payment apps hold off before counting a deposit as complete. Shrinking it to a fraction of a second brings Solana much closer to how a card payment or a centralized exchange trade feels. Ethereum needs roughly 13 minutes to reach full finality, by comparison.
Transaction counts will fall
One effect of the change will look worrying on dashboards. In an email, Robin Nordnes, CEO and founder of Raiku, a company building trading infrastructure on Solana, said there’s no reason to 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.”
Nordnes was also direct about how little faster finality changes things for professional traders. “For desks, faster finality is nice, but it was never the bottleneck. Being close to where the block is built still is,” he said.
Running a validator gets cheaper
For the operators who keep the network running, the cost change could count for more than the speed. Vote fees currently cost validators about 2 SOL a day, and that figure doubled after Solana recently cut its slot times, the window each block gets, to about 200 milliseconds.
Alpenglow does away with vote fees. They’re replaced by a flat entry charge, the validator admission ticket, priced at 0.8 SOL per epoch (a period of about 24 hours). That comes out roughly 60% cheaper.
The timing is deliberate. Over the past year, Solana’s validator network has lost nearly a third of its members.
Bitwise’s latest staking report puts active validators at 659 at the end of September, down from 696 three months before and roughly 30% lower than a year ago. The drop came even though 69% of SOL’s supply is staked. Bitwise pinned the decline on operating costs.
Stake has become more concentrated too. Solana Compass data shows the smallest group of validators that together control more than a third of staked SOL shrank to 18 from 20 over the past year. The share held by the 10 largest validators rose to 24.5% from 22.2%.
Cheaper voting could take some financial pressure off smaller validators. Hardware, bandwidth and hosting costs are untouched and still have to be paid.
Six resets and a rollback
Testing had its problems. According to a post from Galaxy Digital, one of roughly 100 validator operators on the test network, the network was wiped and restarted from scratch six times after going live in early May. One attempt to move to the new system failed across the whole network and had to be rolled back.
A later migration succeeded, which opened the path to Wednesday’s launch. None of this put real money at risk, since the test network is there to absorb that kind of failure.
The switch is scheduled for the start of epoch 1064 on Wednesday. Following a 5,000-slot transition, the change itself takes effect at slot 459,653,000.