Ethereum Faces Challenges with Data-Heavy Blocks After Fusaka Upgrade, Research Reveals

Ethereum is currently experiencing difficulties in processing data-heavy blocks following its December Fusaka upgrade. This has raised questions regarding the network's capability to handle increased data throughput from layer 2 blockchains, as highlighted in new research from MigaLabs.

Key Takeaways:

Ethereum struggles to reliably process data-heavy blocks, despite the Fusaka upgrade introducing higher blob limits.
Blocks containing 16 or more blobs demonstrate significantly higher miss rates compared to standard network conditions.
A surge in layer 2 demand could escalate these high miss rates, potentially jeopardizing Ethereum’s network stability.

The Fusaka hard fork aimed to enhance Ethereum’s data capacity, permitting layer 2 networks to submit more “blobs”—temporary data primarily utilized by rollups to relay transaction information back to the main chain. This upgrade was largely perceived as a significant move towards more affordable and scalable layer 2 operations.

Ethereum Struggles With Data-Heavy Blocks After Fusaka Upgrade, Research Finds

Ethereum Blocks with Increased Blob Counts Encounter Elevated Miss Rates

However, a detailed study by MigaLabs indicates that blocks with a higher number of blobs are much more likely to be missed by the network.

The analysis utilizes data gathered since October 2025, assessing network performance before and after the Fusaka upgrade, along with two following Blob-Parameter-Only (BPO) updates that further elevated blob limits. MigaLabs, known for its partnerships with Lido DAO and the Cambridge Centre for Alternative Finance, discovered that Ethereum has not fully leveraged its increased capacity.

Despite the target blob count being raised recently to 14, the average number of blobs per slot has actually decreased since the initial BPO update. Instances of high blob counts, specifically those with 16 or more blobs, are still quite rare, appearing only a few hundred times out of more than 750,000 examined slots.

What's more concerning is the behavior when blob counts do surge. The study reveals that missed-slot rates increase significantly when blocks consist of 16 or more blobs. While the standard miss rate for slots with up to 15 blobs remains around 0.5%, miss rates for blocks with higher blob counts fluctuate between 0.77% and a troubling 1.79%. In cases with the maximum observed level of 21 blobs, the miss rate exceeded three times the average for the network.

These blobs predominantly come from large layer 2 networks like Arbitrum and Base, which depend on Ethereum for secure data availability. Should demand from these networks rise and high blob counts become commonplace, the increased miss rates could accumulate, posing serious risks to the overall stability of the Ethereum network.

MigaLabs Recommends Halting Blob Capacity Increases Amid Growing Miss Rates

In light of these findings, MigaLabs has advised against any further increases in blob capacity until the miss rates for higher blob counts align more closely with the baseline, and actual demand begins to meet current limits.

Furthermore, it has been reported that the Ethereum Foundation is prioritizing post-quantum security as a strategic initiative, establishing a dedicated Post Quantum team and pledging $2 million to advance this goal. This initiative, announced by Ethereum researcher Justin Drake, will be spearheaded by Thomas Coratger, partnering with Emile, a contributor to leanVM.