# Fusaka Upgrade Impact: Blobs, L2 Fees and Spam

> What the Fusaka upgrade changed on Ethereum, measured before and after: PeerDAS blob capacity, BPO forks, blob fees, layer 2 fees, gas limit and dust spam.

Markdown copy of https://voltfincrypto.com/apps/fusaka-upgrade-impact

**Question:** What did the Fusaka upgrade change for blob capacity, layer 2 fees and Ethereum activity?

- Kind: Report in Voltfin Folio
- Topic: [Layer 2s](https://voltfincrypto.com/topics/layer-2)
- Chains: Ethereum, Base, Arbitrum, OP Mainnet
- Status: Planned. The data is not published yet, so this page states no figure; each figure will open its receipt when it is.

Fusaka is the Ethereum upgrade that activated in December 2025. It added PeerDAS, which lets nodes sample blob data instead of downloading all of it, so that blob capacity could then be raised in steps through small blob-parameter-only forks. This report measures what changed before and after each step, from block headers and receipts.

It covers four effects people ask about: how many blobs blocks carry and what they cost, what users pay on the largest layer 2s, how the block gas limit and mainnet activity moved and whether cheaper transactions brought more dust spam such as address poisoning.

It is written once and dated. Each comparison names the windows and the blocks it was measured over, so a reader can rerun it, extend it to later blob-parameter forks or check any figure against the chain.

## Blueprint

### What Fusaka changed, in one paragraph

The upgrade's main changes and the measured effect of each, with the windows and blocks they were measured over.

Cites: Blobs per block before and after; Median blob base fee before and after; Median layer 2 fee before and after.

### Blob capacity and blob fees

Blobs per block against the target at each step, how often blocks reached the maximum and how the blob base fee and the EIP-7918 reserve price behaved.

Cites: Average blobs per block in each window; Share of blocks above target; Median blob base fee in each window; Blocks priced at the reserve.

### What layer 2 users paid

Median fees per transaction on Base, Arbitrum and OP Mainnet before and after each step, split into execution and data fees.

Cites: Median fee per transaction by chain and window; Data fee share of the median fee.

### Gas limit and mainnet activity

How the block gas limit moved around the upgrade, and how daily transactions and gas used on Ethereum changed over the same windows.

Cites: Block gas limit by window; Daily transactions by window; Gas used per day by window.

### Dust transfers and address poisoning

Daily counts of sub-unit stablecoin transfers, the pattern used to plant lookalike addresses in wallet histories, before and after the upgrade.

Cites: Sub-unit USDT and USDC transfers per day; Addresses receiving dust transfers.

### What to watch next

Later blob-parameter forks, the next network upgrade and the measures that will show whether blob demand catches up with capacity.

## How it will be measured

- Each effect is compared over equal windows before and after each activation (Fusaka, BPO1 and BPO2), using the activation epochs in the fork schedule, so no window straddles a fork.
- Blob figures come from blob_gas_used and excess_blob_gas in every block header; layer 2 fees are median fees per transaction from receipts on Base, Arbitrum and OP Mainnet.
- Dust spam is counted as USDT and USDC Transfer logs on Ethereum worth less than one unit of the token, the pattern address poisoning relies on, per day.
- The gas limit and activity come from block gas_limit and daily transaction counts over the same windows; other causes, such as market moves, are named wherever they overlap a window.
- The report is dated: every figure is pinned to a block before its publication date.

## Data it needs

- `blob_usage_daily` (to build): EIP-4844 blobs posted per day, blob gas used, blob base fee, and the rollup that posted them.
- `gas_blocks` (to build): Base fee, priority fee percentiles, gas used and gas limit for each block on fee-market chains, for a near-live gas tracker.
- `l2_activity_daily` (to build): Per layer 2 per day: transactions, active addresses, fees users paid on the L2, and what the L2 paid Ethereum to settle and post data.
- `chain_activity_daily` (to build): Transactions, active sending addresses, new addresses, contracts created and gas used on each chain per day, counted from blocks and transactions.
- `stablecoin_flows_daily` (to build): Stablecoin mints, burns, transfer volume and active addresses per stablecoin and chain per day.
- Source: blob_gas_used and excess_blob_gas from every block header in each window
- Source: Activation epochs of Fusaka, BPO1 and BPO2 from the fork schedule
- Source: Median fee per transaction per day on Base, Arbitrum and OP Mainnet from receipts
- Source: USDT and USDC Transfer logs on Ethereum with amounts below one token unit
- Source: Block gas_limit and daily transaction counts on Ethereum

## Questions

### What is the Fusaka upgrade?

Fusaka is the Ethereum network upgrade that combined the Fulu consensus-layer fork and the Osaka execution-layer fork. Its main change is PeerDAS, a way for nodes to verify blob data by sampling it, which lets Ethereum raise the number of blobs per block.

### What are BPO forks?

Blob-parameter-only forks, defined in EIP-7892, change only the blob target, the blob maximum and the fee update fraction. They let Ethereum raise blob capacity in steps after Fusaka without bundling the change into a full upgrade.

### Did Fusaka lower layer 2 fees?

The report measures it: median fees on Base, Arbitrum and OP Mainnet over equal windows before and after each step, with the data part of the fee shown apart. Execution fees on each layer 2 also depend on its own demand, so both parts are reported.

### Why would cheaper fees increase address poisoning?

Address poisoning sends tiny transfers from lookalike addresses so that a victim later copies the wrong address from their history. When each transaction costs less, sending many such transfers costs less too, so the report counts sub-unit stablecoin transfers before and after.

### Did Fusaka change the gas limit?

Fusaka capped the gas a single transaction may use (EIP-7825). The block gas limit is signalled by validators and moved separately around the same period, so the report shows it block by block across the windows rather than crediting it to the upgrade.

## Glossary

- **PeerDAS**: Peer data availability sampling (EIP-7594): nodes download and check samples of blob data rather than every blob.
- **BPO fork**: A blob-parameter-only fork (EIP-7892) that changes only the blob target, the maximum and the fee update fraction.
- **Reserve price**: Under EIP-7918, a level tied to the execution base fee below which the blob base fee stops falling.
- **Address poisoning**: A scam that sends tiny or zero-value transfers from lookalike addresses so that a victim later copies the wrong one.

## Related apps

- [Ethereum Blob Fees and Blobs per Block vs Target](https://voltfincrypto.com/apps/ethereum-blob-fees)
- [Next Ethereum Upgrade: Glamsterdam Status and Fork History](https://voltfincrypto.com/apps/next-ethereum-upgrade)
- [Address Poisoning Tracker: Lookalike Address Scams](https://voltfincrypto.com/apps/address-poisoning-tracker)
- [Ethereum Gas Limit Tracker: Block Gas Limit Over Time](https://voltfincrypto.com/apps/ethereum-gas-limit)
- [Ethereum L2 Fees Compared: Cost per Transaction](https://voltfincrypto.com/apps/ethereum-l2-fees)
- [Ethereum TPS: Mainnet and Layer 2 Transactions per Second](https://voltfincrypto.com/apps/ethereum-tps)

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