作者：Data Always - Flashbots Research

Compiled by: Odaily Planet Daily Husband

Data Always, a researcher at Flashbots Research, published an article to demonstrate whether increasing the minimum basic fee for Blob will affect the cost of existing L2 or related transactions. The article summary is as follows:

• The setting of the Blobspace floor price has caused controversy in the community, partly due to a misunderstanding of the path of Blob on the chain. Although it is currently believed that Blob contributes zero to the protocol, this view is only valid when analyzing Blobspace fees.

• Blob-borne transactions still need to pay mainnet gas fees, and during periods of high demand, the impact of gas priority auctions makes L2 transaction pricing more complicated.

• This article demonstrates whether the mismatch between price and demand can be alleviated by increasing the minimum base fee for Blob.

• Overall, this adjustment has limited impact on transaction costs, especially for efficient blob submitters, the fee increase is minimal.

The following is the original text.

The proposal for how to set the blobspace floor price is controversial in the community, but this may stem from a misunderstanding of how blobs find their way on-chain. It is generally believed that blobs currently contribute zero to the protocol, but this only holds true when we restrict our analysis to blobspace fees.

While the blobspace fee market has been slow to reach target demand levels, suffering from the cold start problem predicted by Davide Crapis a year before Deneb, Blob-bearing transactions still pay mainnet gas fees, both for execution and for execution priority. An immediate concern, raised by Max Resnick, is that the hard limit of six blobs per block, combined with a slow response from the blobspace fee market, could lead to long priority gas auctions during periods of high network demand. During these PGAs, L2 transaction pricing becomes more difficult, while strict blob mempool rules make blob inclusion unpredictable.

EIP-77628 aims to minimize the misalignment between future blobspace prices and Blob demand until L2 adoption allows us to overcome the cold start problem. With the currently configured minimum Blobspace base fee set to 1 wei, it will take at least 30 minutes of fully saturated blocks for blobspace fees to reach $0.01 per Blob and begin to affect Blob pricing dynamics. Under the current system, when demand surges, the network reverts to an unpredictable PGA as L2 fights for timely inclusion.

For example, on June 20, the network experienced its second blob reversal event, stemming from the LayerZero airdrop, during which excess demand for blobs lasted for six hours until the network reached equilibrium.

Current status of Blob transaction fees

Six months after Deneb went live, blobspace usage remains below target. As a result, blobspace base fees remain low, and most blobs incur negligible blobspace gas fees. To date, there have only been three weeks where the average cost of blobspace has risen above $0.01 per blob: during the “blobscription” craze on March 25 and April 1, and during the LayerZero airdrop on June 17.

Compared to fees in blobspace, Blob-carrying transactions (also known as Type-3) still require gas fees to execute on mainnet. Despite gas prices falling to their lowest point in many years, the average execution fee per blob is between $0.50 and $3.00. These costs are negligible compared to historical L2 posted call data prices, and blobs are essentially fully subsidized by the network, but this small fee is still important when setting the minimum base fee for blobs.

If we further break down the execution costs of transactions carrying blobs, analyzing them based on their blob content, we see that the market is highly heterogeneous. Transactions carrying only one blob pay the highest fees, while transactions carrying 5 or 6 blobs pay little or no fees per blob. In fact, the total fees paid by these five or six transactions are much lower.

The difference in blob submission strategies of different entities is one of the important reasons for this. Base, OP mainnet and Blast, as well as many smaller L2s, are extremely financially efficient due to publishing data to EOA, which is required for the execution of this strategy. The mainnet gas is only 21,000, regardless of blob count, but these transactions are not suitable for fraud proofing. These chains account for the vast majority of transactions carrying five or more blobs, reducing the perceived price of submitting multiple blobs in a single transaction. In contrast, L2 publishes more complex data to better support fraud proofs, such as Arbitrum, StarkNet, Scroll, ZkSync Era, Taiko, and Linea, uses significantly more mainnet gas, and typically only submits one per transaction. blob.

Based on the statistics above, if we combine the blobspace and execution fees per transaction, we see that, except for brief spikes in Blob demand (which would not be affected by increasing the minimum base fee), the current distribution of blobspace fees paid is almost entirely concentrated in execution fees. This suggests that the blobspace fee market is not currently functioning properly, and there is a lot of room to increase the minimum fee for blob gas without significantly increasing the total cost of Blob payments.

In contrast, if we focus on the period when the blobspace fee market enters price discovery, fee density quickly shifts towards blobspace fees. When the market works, it seems to work well. Therefore, the most important issue is the recurring cold start problem - the dilemma the market is currently facing.

When the blobspace fee market is in an execution fee dominated environment, blob submitters who publish less execution data (mostly OP Stack chains) benefit. It also complicates the block construction process: many algorithms historically decided blob inclusion by preferred fees per gas, but since mainnet gas usage for these transactions varies widely, it forces L2s that submit higher quality proofs to pay higher rates for all the larger transactions, further amplifying the advantage of submitting less execution data. By approaching a blobspace fee dominated environment, we weaken this advantage.

Impact of minimum fees

At current ETH prices, Max’s original proposal set a minimum fee of $0.05 per blob. By supplementing execution costs with this new minimum fee, the proposal would increase the average cost per blob by 2%.

The revised proposal reduces the minimum blob base fee to 2^25, about one-fifth of the original proposal value, or $0.01 per blob. This represents a 0.7% increase in the average cost of a blob since the beginning of July, but the percentage change is not uniform across entities due to differences in financial efficiency between blob submitters.

Modify earlier per-transaction fee analysis to consider a minimum blobspace base fee of 2^25 wei, and only consider transactions where the original blobspace base fee is lower than the new proposed minimum fee. We see that while the fee structure is starting to change significantly, the blob base fee remains a minority component for all affected blob carrying transactions. Efficient transactions submitted by Base and OP Mainnet (carrying five blobs) will see a 10% to 30% fee increase based on L1 gas prices, a change that should be easily absorbed. Less efficient transactions, especially those carrying one to three blobs, will see fee increases of less than 10%.

Table: Blob submission statistics by entity from July 1, 2024 to September 17, 2024, assuming an ETH price of $2,500.

Modifying the previous per-transaction breakdown to consider a minimum blobspace base fee of 2^25 wei, and only considering transactions with an original blobspace base fee lower than the proposed new minimum fee, we see that while the fee structure is starting to change significantly, The Blob base fee remains a fraction of all affected Blob hosted transactions. Efficient transactions (carrying five blobs) submitted by Base and OP Mainnet will see a 10% to 30% fee increase based on L1 gas prices, a change that should be easily absorbed. Less efficient transactions, especially those carrying one to three blobs, will see fee increases of less than 10%.

To date, there are no Blob-carrying transactions where the minimum Blob base fee of 2^25 accounts for the majority of payment costs on exchanges.

Blobspace response time

Under EIP-4844, the maximum inter-block update of the blobspace base fee is 12.5%. Starting from a price of 1 wei, it takes 148 maximum-capacity blocks and over 29 minutes (12 seconds of block time) for the base fee to rise above 2^25 wei. This update period has been defined as the response time of the protocol, but it still only represents a minimum amount of time. Due to market inefficiencies, blocks are not fully loaded with blobs, significantly extending the time to price discovery.

Prior to the LayerZero airdrop on June 20, the blob base fee was at its lowest value of 1 wei. At its peak, the blob base fee reached 7471 gwei ($3,450 per blob). Although this height could theoretically be reached in 51 minutes, the actual increase took nearly six hours. Under Max's proposal, this peak could theoretically be reached in 21 minutes, but these theoretical values ​​are obviously not accurate.

The goal of the proposal is to set the minimum blob base fee close to the tipping point where blobspace fees start to take up a measurable share of total fees, rather than focusing on timing. On June 20, despite the surge in blob volume starting after 11:00 UTC, blobspace fees did not begin to account for 0.1% of total fees paid by blobs until 15:17 UTC, and did not exceed the base fee of 2^25 wei (0.0335 gwei) until 15:41 UTC.

In contrast, if the minimum base fee during the LayerZero airdrop is 2^25 wei, the network may skip the cold start problem and minimize the misalignment between price and demand. As shown in the figure below, we can predict that the blob market will still take an hour or more to normalize.

In summary, raising the minimum blobspace base fee is not a panacea, but it should be viewed as a welcome change to the protocol. The market impact of the proposal should be minimal, with only the cheapest and lowest quality blobs seeing more than a 1% price increase, while still being significantly lower than their competitors.