Solana starts testing upgrade that could cut finality from 12.8 seconds to 150 milliseconds

# Solana starts testing upgrade that could cut finality from 12.8 seconds to 150 milliseconds

> Evidence tier: B1
> Evidence type: Independent digital asset media report
> Source: [CoinDesk](https://www.coindesk.com/tech/2026/09/23/solana-starts-testing-upgrade-that-could-cut-finality-from-12-8-seconds-to-150-milliseconds)
> Published: 2026-09-23
> Captured: 2026-09-23T12:38:31.003Z

## Source summary

CoinDesk reports that Solana's Alpenglow consensus upgrade has moved to its public testnet, where developers will test a target of cutting transaction finality from about 13 seconds to 0.15 seconds. Alpenglow replaces TowerBFT with Votor, which aims to finalize blocks in one or two voting rounds. This is a testnet migration: the tentative Sept. 28 date concerns Agave 4.3 mainnet features, not a confirmed Alpenglow launch.

## Why it matters

Faster finality could shorten the wait exchanges, bridges and merchants need before treating a transaction as irreversible. That could matter for payment confirmation and settlement, but the 0.15-second figure is a test target; no mainnet performance or merchant adoption is demonstrated yet.

## Key numbers

- **Current transaction finality described in the article:** about 13 seconds
- **Alpenglow test target:** 0.15 seconds

## Topics and entities

- Industry lane: Web3 & stablecoin payments
- Entities: Solana / Anza
- Web3 payments
- Payment infrastructure

## Evidence and credibility note

Independent CoinDesk reporting confirms a public-testnet migration, not mainnet deployment. The 0.15-second figure is a target; CoinDesk explicitly says Sept. 28 is not a confirmed Alpenglow launch date.

Date evidence: Automatically verified from JSON-LD datePublished: 2026-09-23T05:16:22.933Z

## First-party corroboration

No directly corresponding A1 company announcement is currently linked.

## Original-source traceback

[Open the original CoinDesk report](https://www.coindesk.com/tech/2026/09/23/solana-starts-testing-upgrade-that-could-cut-finality-from-12-8-seconds-to-150-milliseconds)

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This is a structured Payments Hot Markdown source summary derived from external reporting. Use the original link above to read the publisher's article; copyright remains with the original publisher.