Solana Raised Block Capacity 66%. One Limit Explains What the Upgrade Can and Cannot Fix

Solana has made its largest block-capacity jump in years.

The network can now accept 100 million compute units of work in a block, up from 60 million.

That is a 66% increase without a new chain, a token migration or an application rewrite.

It also comes with a boundary that matters during the exact moments when traders care most.

Solana raised the ceiling for the whole block.

It did not raise the 12 million compute-unit ceiling for a single writable account.

100M CU blocks are live on mainnet.

SIMD-0286 raises the block limit from 60M → 100M compute units. 66% more capacity. https://t.co/4RWPIfx1Bw

— Solana (@solana) July 29, 2026

The upgrade, known as SIMD-0286, activated on mainnet at the start of epoch 1009 on July 29.

Compute units are Solana’s meter for transaction work. A simple token transfer consumes less compute than a complicated trade, liquidation or smart-contract instruction.

Each block has a budget. Once the network reaches that budget, a leader cannot keep adding transactions even if there is room elsewhere in the data structure.

Moving from 60 million to 100 million compute units gives every block a much larger work allowance.

The Solana Foundation’s activation summary says the change increases capacity for high-volume trading and payments while preserving the network’s roughly 400-millisecond slot time. Applications and indexers do not need a breaking-format change, and the upgrade already ran on testnet and devnet before reaching mainnet.

The same summary shows why engineers were willing to make an aggressive jump. From July 22, 2025, when the 60 million limit arrived, through the new activation, 11.2% of blocks used at least 56 million compute units.

That means roughly one block in nine was already running close to the old ceiling.

The pressure was concentrated around bursts of activity. Volatile trading, popular token launches and fast-moving liquidations tend to create demand at the same time, forcing users to compete for blockspace when delays are most expensive.

The new limit gives Solana room to absorb more of those bursts.

It does not guarantee that every crowded application suddenly becomes congestion-free.

The separate writable-account limit explains why.

A writable account is an onchain account that a transaction changes. A busy liquidity pool, order book or market program can become a shared destination for thousands of transactions.

Solana still limits any one writable account to 12 million compute units per block.

Under the old 60 million block ceiling, one hot account could consume as much as 20% of a block’s total compute budget. Under the new 100 million ceiling, the same account can consume 12%.

Unrelated applications gain more room around that hot spot.

The hot spot itself reaches its account-level ceiling at the same point.

The SIMD-0286 technical proposal makes that design choice explicit. It changes max block units to 100 million while keeping max writable-account units at 12 million, max vote units at 36 million and the block account-data delta at 100 megabytes.

The document says a larger block budget lets validators include more transactions without changing the limits that protect individual shared accounts or vote traffic. It also records the rollout sequence: the feature first activated, validators upgraded their software, and the higher ceiling switched on only after the cluster reached the designated epoch.

That staged approach matters because block capacity is a network-wide setting. A validator running software that cannot recognize the new limit could otherwise disagree with the rest of the cluster about which blocks are valid.

The proposal’s author, Lucas Bruder of Jito Labs, framed the extra room as parallel capacity. More independent transactions can fit together, while the network avoids letting one heavily contested account dominate the entire block.

An 80 million compute-unit limit was considered.

The proposal chose the full 100 million jump.

Last year, @buffalu__ authored SIMD-0286, which proposed raising the block limit to 100m CUs. Today, it was finally merged—a major step in increasing bandwidth for Solana.

Block space on Solana is a finite resource that block producers have to carefully budget when packing… https://t.co/4KxcZEOmH8

— Jito (@jito_sol) July 29, 2026

There was another obstacle before Solana could safely push larger blocks across the network.

Validators have to receive, verify and replay each block quickly enough to stay synchronized.

A larger block carries more work and usually more data. If propagation slows too much, validators can fall behind, block production can become less reliable and powerful operators gain an advantage over smaller ones.

Solana’s answer is XDP, or eXpress Data Path.

The Solana Foundation describes XDP as a Linux networking path that lets validator software process packets before they travel through the normal kernel stack, reducing copies, context switches and other processing that can slow the delivery of a large block. Agave 4.0 and later support it as an opt-in feature, while Firedancer uses it by default across validators running that independent client.

The Foundation says the change lowers packet-processing overhead and improves the rate at which validators can receive block data, a prerequisite for raising block capacity without stretching slot times. Its rollout report tracked adoption by stake because the network benefits only when a large share of voting power can handle the faster path.

More than 70% of mainnet stake had enabled XDP before the 100 million compute-unit gate activated, and Agave 4.2 is expected to make the feature the default. The capacity increase therefore rests on faster validator networking as well as a higher configuration limit.

That adoption gave engineers confidence that blocks could move through the validator set quickly enough to preserve current slot timing.

The performance risk has not disappeared.

Bigger blocks take longer to execute. Validators that fall behind may need more time to catch up, and infrastructure outside the validator set — including RPC providers, exchanges and indexers — must be able to handle sustained full blocks even though the underlying data format did not change.

Solana Compass connects the activation to the network’s recent demand pattern. Decentralized exchanges, order books and applications that spread work across many independent accounts stand to gain first because they can use the added parallel room.

Its analysis notes that the increase followed the 2025 move from 50 million to 60 million compute units, making this the second major capacity expansion in roughly a year. It also highlights the unchanged 12 million writable-account limit as an intentional safeguard against a single congested market consuming the larger block.

That means the upgrade can admit more unrelated activity at once, but it cannot remove every application-specific bottleneck. The distinction is important for traders: broad network saturation and contention around one popular account are different problems, and SIMD-0286 directly addresses only the first.

The upgrade is therefore a capacity increase, not a universal cure.

A payment app sending value across many accounts can fit more activity into each block.

Several markets operating at once can crowd each other less.

A single trade venue built around one heavily contested account can still hit the 12 million limit and leave users fighting for access to that specific resource.

That distinction is easy to lose in the 66% headline.

Solana doubled block compute from the 50 million starting point it used before last year’s increase. It did so while keeping the per-account write limit flat and preserving the guardrails around vote compute and data growth.

The network is betting that parallel demand will continue to grow faster than any one application’s need to monopolize a block.

If that bet is right, traders should see more room during broad market surges, developers can build heavier applications and payment activity can expand without every workload colliding with the same block ceiling.

If congestion remains concentrated in a handful of hot accounts, users may still encounter failed or delayed transactions inside those markets.

The 100 million figure shows how much larger Solana has become.

The unchanged 12 million figure shows where its next bottlenecks will appear.

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