Solana Switches On Alpenglow, Replacing Its 2020 Consensus Engine
By Coinvote
Solana validators retired TowerBFT on Wednesday and moved the network to Alpenglow, a consensus design targeting finality of about 150 milliseconds. Outlets agree on the target but differ on the baseline, and early dashboard readings still showed slower confirmation.
Validators hand off to Alpenglow on the live network
Solana moved to Alpenglow on Wednesday, ending the TowerBFT consensus protocol that had run the network since March 2020, according to Decrypt. Validators retired the old system at slot 459,653,000 at around 14:00 UTC. They switched on the running network and carried the existing ledger forward, with independent operators agreeing on a shared handoff point.
Cointelegraph put the mainnet activation at around 1:54 pm UTC, citing the Solana Foundation's Alpenglow dashboard. CoinDesk had set out the schedule beforehand: the switch was due at the start of epoch 1064, with the change at the same slot after a 5,000-slot transition.
The Block described the launch as Anza's upgrade and said it cuts finality from 12.8 seconds to about 150 milliseconds. Anza is the core engineering team that maintains the Agave validator software, where Alpenglow was implemented.
How direct voting changes what finality means
Finality marks when a transaction becomes irreversible. Exchanges, banks and merchants typically wait for it before they consider funds to have moved. Decrypt reported that TowerBFT gave a conditional confirmation within seconds but needed a longer second step for full finality, and that Alpenglow folds those two steps into one.
CoinDesk explained the mechanism. Under the old design, every validator wrote its votes onto the blockchain like an ordinary transaction. Under Alpenglow, votes no longer sit on the chain. They are grouped into certificates, and a transaction can be locked in after either one or two voting rounds.
Anza head of research Roger Wattenhofer told Solana Foundation executive Jacob Creech that once 80% of stake votes yes, a block is immediately final. A second route uses two voting rounds that each need 60% of stake, and it can be faster for validators clustered close together. Decrypt added that the protocol is designed to keep functioning even if less than a fifth of stake behaves maliciously and another fifth is offline.
The key figures at a glance
The reported numbers come from different outlets and measure slightly different things.
- Finality target: roughly 150 milliseconds, per Decrypt, Cointelegraph and CoinDesk.
- Baseline cited by Decrypt, Cointelegraph and The Block: about 12.8 seconds.
- Governance: validators approved the proposal, SIMD-0236, with 98% in favor in September 2025, according to Decrypt.
- Development time: Anza says it took the design from white paper to mainnet in under 18 months.
- Dashboard reading at press time: 6.6-second finality and 4,721 transactions per second, per Cointelegraph.
Where the outlets' accounts diverge
The biggest gap is the starting point. Decrypt, Cointelegraph and The Block all measure the old finality at about 12.8 seconds. CoinDesk instead says a payment is locked in after about six seconds and describes the new target as roughly 40 times faster. The reports do not explain why the baselines differ.
Cointelegraph framed the goal as a 99% reduction, citing the Solana Foundation's July announcement. It also noted that the dashboard still showed 6.6 seconds of finality at press time, and that it had asked the Solana Foundation how the testnet measurements compare with expected real-world performance. The Block's coverage is limited to its headline and summary, so it adds no detail beyond the two headline figures.
Timing also varies slightly, with Decrypt giving around 14:00 UTC for the slot handoff and Cointelegraph reading 1:54 pm UTC from the dashboard. Both describe the same event as happening shortly before 14:00 UTC.
Cheaper voting, fewer validators and a pending block-size debate
CoinDesk reported that vote fees cost validators roughly 2 SOL per day, and that this expense doubled once Solana shortened its slot time to about 200 milliseconds. Alpenglow replaces those fees with a flat validator admission ticket of 0.8 SOL per epoch, an epoch lasting about 24 hours. CoinDesk puts that at roughly 60% cheaper.
That matters because the validator set has been shrinking. CoinDesk cited Bitwise's latest staking report, which counted 659 active validators at the end of September, down from 696 three months earlier and roughly 30% below a year ago. Bitwise attributed the decline to operating costs. The minimum number of validators controlling more than a third of stake fell to 18 from 20, according to Solana Compass data, while the top ten's share rose to 24.5% from 22.2%. CoinDesk noted that hardware, bandwidth and hosting costs remain.
Robin Nordnes, CEO of Raiku, told CoinDesk that visible transaction counts will look lower because vote transactions are no longer on-chain. He added that for trading desks, proximity to where the block is built has been a bigger bottleneck than finality. Separately, Decrypt reported that Firedancer developers at Jump Crypto have proposed removing the 60 million compute unit cap per block, and critics warn that could favor well-funded operators.
What to watch after the switch
The first open question is whether mainnet finality reaches the 150-millisecond target. The dashboard reading of 6.6 seconds in Cointelegraph's report shows the figure had not yet been demonstrated at that moment. Readers can track the Solana Foundation's Alpenglow dashboard for updated measurements.
More protocol work is queued. Rotor is intended to replace the Turbine data-distribution layer, and a leader rotation that accounts for geography is meant to reduce delays when block production passes between validators. Decrypt said Quantumglow, a research design for quantum-resistant signatures, has no committed date. Cointelegraph reported that Agave 4.5, planned for December 2026, proposes raising the accounts per versioned transaction from 64 to 96.
On the market side, Cointelegraph said the SOL price rose nearly 3% in the 24 hours before the upgrade but remains down 42% over the past year, according to CoinMarketCap. DefiLlama shows Solana with $6.02 billion in DeFi total value locked, against $50.67 billion on Ethereum. Teams and traders following new projects on the network can check the new Solana tokens listed on Coinvote, which shows 48 listings in the last seven days.
Market snapshot
| Asset | Price | 24h | 7d | Market cap |
|---|---|---|---|---|
| Ethereum (ETH) | $2,499 | +2.6% | +1.6% | $305.56 billion |
CoinGecko data as of 2026-10-21 (UTC); DeFi TVL from DefiLlama: Ethereum $50.67 billion, Solana $6.02 billion.
On Coinvote
- New Solana Tokens Listed Today: 3,699 projects tracked, 48 new listings in 7 days, 257 community votes today.
- Best Solana Meme Coins Today: 2,415 projects tracked, 28 new listings in 7 days, 195 community votes today.
- New Ethereum Tokens Listed Today: 2,926 projects tracked, 1 new listing in 7 days, 1 community vote today.
- Best Ethereum Meme Coins Today: 256 projects tracked, 0 new listings in 7 days, 0 community votes today.
FAQ
What is Solana's Alpenglow upgrade?
Alpenglow is a new consensus protocol that replaced TowerBFT, which Solana had used since March 2020. Validators now vote directly with each other and bundle votes into certificates, which is meant to cut finality to roughly 150 milliseconds.
How fast is Solana finality after Alpenglow?
The target is roughly 150 milliseconds, down from about 12.8 seconds according to most outlets. Cointelegraph reported that the Solana Foundation's dashboard still showed 6.6 seconds at press time.
Why will Solana's transaction count look lower?
Raiku CEO Robin Nordnes told CoinDesk that most previously counted transactions were validator votes, which are now off-chain. He said the trading activity itself is unchanged.
Sources
- The Block: Anza’s Alpenglow goes live on Solana, cutting finality to 150 milliseconds (2026-10-21)
- Decrypt: Solana Alpenglow Goes Live in 'Most Ambitious' Upgrade Since Ethereum's Merge (2026-10-21)
- Cointelegraph: Solana’s Alpenglow launches on mainnet, targets 99% faster finality (2026-10-21)
- CoinDesk: Solana’s Alpenglow, its biggest network overhaul since 2020, goes live Wednesday (2026-10-21)
- CoinGecko (market data), DefiLlama (TVL), Coinvote listing and vote data
Written by the Coinvote news desk from reporting by The Block, Decrypt, Cointelegraph and CoinDesk. Not financial advice.
