New network data suggests that ethereum blobs may be stressing the chain’s ability to handle surging layer 2 activity after the recent Fusaka upgrade.
Summary
Fusaka upgrade impact on Ethereum’s data throughput
The Fusaka hard fork, activated in December, was promoted as a major step toward cheaper and more scalable layer 2 activity on Ethereum. It expanded the network’s data capacity by allowing rollups to submit more temporary data, known as blobs, which they use to post batched transaction information to the main chain.
However, new analysis from MigaLabs indicates that the network is struggling under data-heavy conditions, even with these higher limits. The findings raise questions about whether Ethereum is ready to sustain significantly higher throughput from rollups, especially if demand accelerates in 2025 and beyond.
Data-heavy blocks show elevated miss rates
The study, titled “Ethereum Blocks With Higher Blob Counts Face Higher Miss Rates,” examines validator performance using data collected since October 2025. It compares network behavior before and after Fusaka, as well as two subsequent Blob-Parameter-Only (BPO) updates that further raised blob limits.
MigaLabs, which has previously worked with Lido DAO and the Cambridge Centre for Alternative Finance, concludes that Ethereum is not yet using its expanded capacity efficiently. Despite an increase in the target blob count, most recently lifted to 14, the median number of blobs per slot has actually fallen since the first BPO update.
Moreover, very high blob counts remain uncommon. Blocks carrying 16 or more blobs have appeared only a few hundred times out of more than 750,000 observed slots. That said, when those high data loads do appear, they coincide with a sharp rise in missed-slot rates across the network.
Miss rates spike beyond 15 blobs
The MigaLabs research finds that the baseline miss rate for slots with up to 15 blobs is around 0.5%. However, once blocks carry 16 or more blobs, miss rates climb into a range between 0.77% and as high as 1.79%, significantly above normal network conditions.
At the maximum observed level of 21 blobs in a single slot, the miss rate was reported to be more than three times the network average. These data heavy blocks are primarily generated by large layer 2 networks such as Arbitrum and Base, which depend on Ethereum’s data availability for their security guarantees.
Moreover, the analysis notes that if layer two demand rises and these elevated blob levels become routine, the higher miss rates could compound. This dynamic might threaten overall network stability, especially during periods of market stress or surging transaction volumes.
MigaLabs calls for caution on further blob capacity increase
According to the report, the pattern of rising slot misses at higher blob counts is consistent across all observed data points, even if the sample size for the most extreme values remains limited. MigaLabs therefore argues that the current blob miss rates should be treated as a warning signal rather than an anomaly.
In its conclusion, the firm recommends pausing any further blob capacity increase until miss rates at the top end of usage move back toward the baseline. Furthermore, it argues that real demand should first approach the existing limits before developers consider raising them again, to avoid unnecessary stress on validator infrastructure.
The report also highlights how ethereum blobs function as a core resource for rollups, making stable data availability crucial for the wider scaling roadmap. If high-throughput rollups continue to push usage toward the upper end of the blob range without corresponding improvements in reliability, Ethereum’s role as a secure data layer could be called into question.
Broader roadmap and security priorities
The performance concerns around blobs arrive as the Ethereum community promotes its broader scaling roadmap. A recent post describing “Tomorrow: Fusaka” framed the upgrade as the network’s second major change this year, with a feature highlight on PeerDAS, a technique expected to unlock up to 8x data throughput for rollups.
For rollup teams, that promise translates into potentially cheaper blob fees and more room to grow on-chain activity. However, MigaLabs’ findings suggest that improving raw capacity alone is insufficient if validator performance degrades at the upper end of usage.
At the same time, the Ethereum Foundation is stepping up work on long-term security. As reported, it has made post-quantum resilience a core strategic priority, forming a dedicated Post Quantum team and committing $2 million to the effort. The initiative, announced by researcher Justin Drake, will be led by Thomas Coratger alongside Emile, a contributor to leanVM.
Altogether, the latest fusaka upgrade impact, combined with growing attention to cryptographic robustness, shows Ethereum navigating a delicate balance. It must scale data throughput for rollups while ensuring that reliability, validator performance and long-term security remain firmly in focus.
In summary, the MigaLabs analysis underscores that Ethereum’s path to higher throughput is not just about raising limits but also about maintaining stable operations under stress, as real-world usage gradually pushes the protocol toward its current blob ceilings.
