Ethereum’s Fusaka Upgrade Hits Speed Bump: Data-Heavy Blocks Create Network Strain, Research Reveals

Ethereum's latest evolution isn't going entirely to plan. Fresh research indicates the network's post-Fusaka landscape is grappling with a significant, perhaps predictable, growing pain: bloated, data-heavy blocks that are testing the limits of its new architecture.

The Bandwidth Bottleneck

The core promise of Fusaka—enhanced scalability and efficiency—is facing its first major stress test. Blocks are packing in more data than the upgraded framework seems to comfortably handle, creating network congestion and raising questions about optimal throughput. It's the classic tech dilemma: you build a wider highway, and suddenly everyone wants to drive a freight truck.

Scaling Pains or Design Flaws?

Initial analysis suggests this isn't a failure but a scaling challenge. The upgrade successfully unlocked new capacity, and the ecosystem is aggressively filling it—perhaps too aggressively. Validators and node operators are now navigating the practical realities of these denser blocks, which demand more resources to process and propagate. It’s a high-class problem that still needs solving.

The Road Ahead: Optimization or Overhaul?

The path forward hinges on layer-2 solutions and client optimizations picking up the slack. The community's response will be a critical indicator of Ethereum's adaptive resilience. Expect a flurry of client updates and renewed debate over block size parameters in the coming weeks. After all, what's a major upgrade without a few frantic post-launch patches?

For now, the network presses on, working through the kinks. It's a reminder that in crypto, even the most bullish upgrades meet the immutable law of unintended consequences—usually right after the celebratory tweets fade and the developers go back to their coffee-stained keyboards.

Ethereum Blocks With Higher Blob Counts Face Higher Miss Rates

However, an empirical analysis published by MigaLabs suggests that blocks carrying higher blob counts are significantly more likely to be missed by the network.

The research draws on data collected since October 2025 and examines network behavior before and after Fusaka, as well as two subsequent Blob-Parameter-Only (BPO) updates that raised blob limits further.

MigaLabs, which has previously collaborated with Lido DAO and the Cambridge Centre for Alternative Finance, found that Ethereum is not coming close to using the expanded capacity.

Despite increases to the target blob count, most recently raised to 14, the median number of blobs per slot has actually fallen since the first BPO update.

High blob counts of 16 or more remain rare, appearing only a few hundred times out of more than 750,000 observed slots.

More troubling is what happens when blob counts do spike. The study shows that missed-slot rates rise sharply once blocks contain 16 or more blobs.

Tomorrow: Fusaka

Ethereum’s second major upgrade this year.

→ Feature highlight: PeerDAS – Unlocking up to 8x data throughput. For rollups, this means cheaper blob fees and more space to grow.

Learn more. https://t.co/3TOda5KjY2 pic.twitter.com/sEfeiTamy9

While the baseline miss rate for slots with up to 15 blobs hovers around 0.5%, miss rates at higher blob counts range from 0.77% to as high as 1.79.

At the maximum observed level of 21 blobs, the miss rate was more than three times the network average.

These blobs are primarily submitted by large layer 2 networks such as Arbitrum and Base, which rely on Ethereum’s data availability to operate securely.

If demand from these networks increases and high blob counts become more common, the elevated miss rates could compound and pose risks to overall network stability.

MigaLabs Urges Pause on Ethereum Blob Increases Amid Rising Miss Rates

MigaLabs cautioned that while the sample size for very high blob counts is still limited, the pattern is consistent across all observed data points.

In its conclusion, the firm recommended against any further increases to blob capacity until miss rates at higher blob levels return to baseline and real demand begins to approach existing limits.

As reported, the Ethereum Foundation has elevated post-quantum security to a core strategic focus, forming a dedicated Post Quantum team and committing $2 million to the effort.

Announced by Ethereum researcher Justin Drake, the initiative will be led by Thomas Coratger alongside Emile, a contributor to leanVM.