Ethereum Pectra blob fee market: five myths vs facts

Capacity and pricing dynamics

Pectra increased the target and maximum blobs per block to 6 and 9 through EIP-7691. This change expanded daily data capacity to 8.15GB, which is higher than the 5.5GB capacity available under the previous 3/6 configuration. Rollups purchase 25,600 blobs daily, an increase from the 21,200 blobs purchased daily in the 60 days before the upgrade. Demand remains 33% below the new target of 6 blobs per block. Consequently, blobs are virtually free again. Rollups pay less than one-thousandth of a penny daily. The median cost per blob object remains $0.00000000035. Total blob object costs since Pectra went live amount to only $0.0000395. While capacity grew, only 3.3GB of dataspace is being purchased daily. This amount equals 40% of the maximum available capacity and 61% of the target rate. The amount of data capacity used in blobs is 86% full on average post-Pectra, compared to 82% in the 60 days before the upgrade.

Parameter	Pre-Pectra	Post-Pectra
Target Blobs per Block	3	6
Max Blobs per Block	6	9
Daily Data Capacity	5.5GB	8.15GB
Min Base Fee	1 wei	0.034 gwei

Rollup expenses and margin fluctuations

Scrutiny of rollup cost claims reveals a disconnect between data availability costs and end-user fees. While rollups paid a daily average of $11,015 for blob-related costs since Pectra, this is a 51% decline from the $20,660 average in the 60 days before the update. This reduction includes both blob object costs and type-3 execution layer transaction costs. However, transaction costs on some top rollups stayed the same or even increased slightly since Pectra was activated. This occurs because the Ethereum layer 1 base fee increased more than 650% week-over-week in the days following activation. This spike in l1 fees helped keep the total costs paid by rollups elevated. In the 60 days before the upgrade, 11.22 ETH burned daily on average, with execution layer fees making up 37.1% of that total. Since Pectra, only 3.26 ETH burns daily, and 99.99% of that burned ETH comes from base fees of type-3 execution layer transactions. This represents a 71% decline in total daily ETH burned for rollup data. Linea and Base maintain margins of 98.86% and 98.54% after onchain costs. Blast saw its percent margins grow from the high 50% range to over 80%. You should know that blob fees do not appear in standard consumer wallets because rollups handle those transactions.

EIP-7762 and the price discovery process

Vitalik Buterin supports EIP-7762 to increase the minimum base fee from 1 wei to approximately 0.034 gwei. This change aims to speed up price discovery by pushing rollups toward a stable price range. Currently, it takes approximately 190 blocks where each block contains 6 blobs for the base fee to climb from 1 to 5 gwei. With the new minimum, that duration drops to 42 blocks. To prevent extreme spikes in the blob base fee after the fork, developers must reset the excess gas. If the excess gas is not reset, the base fee could skyrocket because the minimum base fee acts as a multiplier. Such a spike would force rollups to wait for a period before the price calms down again. This ensures the fee market moves toward a stable price range without unpredictable volatility.

Node data and storage requirements

Increased blob demand affects the storage requirements for consensus layer nodes. These nodes must hold rollup blob data for at least 18 days before they can remove it from their machines. The increase in the number of blobs purchased daily has pushed the amount of data that consensus layer nodes must maintain between pruning to a new high estimate of 44.6GB. Before Pectra, nodes consistently carried between 40GB and 44GB of data. If current demand levels stay, nodes will carry around 60GB. At the target rate, nodes will carry between 95GB and 100GB. Will the increase in node storage requirements eventually force a change in consensus client architecture?