Arbitrum switched on Priority Gas Auctions (PGA) at 1:20 p.m. ET on Sept. 23 on Arbitrum One, retiring the Timeboost mechanism that had run on the network since April 2025, according to an on-chain transaction and an X post from the project on Sept. 24.

The new ordering system lets users bid for execution priority through the standard EIP-1559 priority-fee field, transaction by transaction. Arbitrum said both PGA and Fast Feed, a paid transaction-data product, were "now live" on Sept. 24.

How does PGA differ from Timeboost?

Timeboost, launched in April 2025, auctioned control of a 60-second express lane through sealed bids. Transactions outside that lane faced a 200-millisecond delay while the round's controller held the auction. Bidders had to build specialized tools and forecast trading opportunities across an entire upcoming round.

In a June 16 governance analysis titled "Constitutional AIP: Transition Arbitrum One ordering policy to Priority Gas Auctions (PGA)," Entropy Advisors, which advised Offchain on ordering policy, said Timeboost had generated about $7.46 million in fees since launch. Three entities accounted for about 97% of auction wins under the old mechanism.

PGA eliminates the express lane and its 200-millisecond delay. Arbitrum's documentation describes two nominal 125-millisecond ordering rounds operating within the network's unchanged 250-millisecond block window.

How do the new ordering rounds actually rank bids?

The sequencer ranks bids within each round, applying a waiting-time boost for patience and breaking ties by arrival time. A higher bid cannot interrupt a round already underway.

Users can still submit transactions without a priority tip, paying only the base fee. Queued transactions receive a virtual priority boost across rounds, raising their position without increasing their cost. The mechanism targets zero-tip and low-tip transactions that would otherwise wait indefinitely.

PGA proceeds require periodic accounting and a separate DAO distribution vote every six months. The allocation framework replicates Timeboost's split: 97% of priority-fee revenue flows to the Arbitrum DAO treasury and 3% to the Arbitrum Developer Guild.

What does Fast Feed actually deliver?

Fast Feed serves a separate function. Subscribers see individual transactions after the sequencer orders and executes them, rather than waiting for the completed block feed. The product targets searchers and market makers who need earlier reads on-chain activity to position the next transaction.

The subscription fee does not buy execution priority. Access requires an on-chain ticket purchase and an authenticated connection. Entropy Advisors wrote that it selected USDG as the subscription settlement asset with OAT's approval.

A dedicated revenue contract routes 97% of subscription proceeds to the DAO treasury and 3% to the Developer Guild. The feed never exposes pending transactions in the private mempool, and subscribers cannot insert a transaction ahead of one already published.

What risks should Fast Feed subscribers weigh?

A sequencer failure before block completion can drop an advertised transaction from the final block. Arbitrum's documentation tells subscribers to confirm final state against a node or the standard sequencer feed.

Both products now operate under the same 97/3 revenue split that governed Timeboost, but PGA adds a procedural step: the next Arbitrum DAO vote on distribution timing falls six months from the Sept. 24 go-live.