Solana Network News on July 29, 2026: What the 100M CU Block Upgrade Changes
Solana raised its block compute limit from 60 million to 100 million CUs. Here is what the 66% capacity increase changes for payments, trading, validators, and congestion.
Solana network news on July 29, 2026: the 100M CU upgrade is live
Solana raised its maximum block compute limit from 60 million to 100 million compute units on July 29, 2026, a 66% increase in block capacity. The feature activated on mainnet at the start of epoch 1009 after earlier testnet and devnet activation.
The change gives validators more room to include transactions in each block without changing the roughly 400-millisecond slot time cited by the Solana Foundation. It is designed to help the network absorb bursts of trading, payments, and other onchain activity that previously pushed blocks close to the 60 million CU ceiling.
It is not a blanket promise that every Solana transaction will become faster or cheaper. A popular program can still hit its own account-level constraint, and larger blocks create more work for validators, RPC providers, indexers, and exchanges.
1. Compute units measure work, not a fixed transaction count
A compute unit, or CU, is Solana's way of measuring the processing work performed by a transaction. Simple transfers use fewer CUs than complex transactions that call several programs or perform more calculations.
That is why the new 100 million CU limit should not be read as a fixed number of transactions per block.
The actual count depends on the mix of activity. A block filled with simple transfers can contain more transactions than one filled with compute-heavy trading or decentralized-finance operations.
SIMD-0286, the Solana improvement document behind the change, raises only the maximum compute allowed across an entire block. It does not change the maximum size of an individual transaction or rewrite how applications request compute.
For users, the practical point is straightforward: validators have a larger work budget for each block, so unrelated activity has more room to land during demand spikes.
2. The upgrade adds parallel capacity, not unlimited room for one hot market
Solana kept the maximum writable-account limit at 12 million CUs.
That limit controls how much compute can write to one account during a block. It helps prevent a single congested account or program from consuming all available block capacity.
Under the previous 60 million CU block limit, 12 million CUs represented as much as 20% of the block. Under the new 100 million CU limit, the same account ceiling represents 12%.
This is the most useful way to understand the upgrade.
A heavily used market or application can still reach the same account-level ceiling. The difference is that its activity crowds out a smaller share of the full block, leaving more capacity for transfers and applications using other accounts.
The upgrade therefore favors broader parallel activity across the network. It does not remove every local congestion point.
3. Solana had evidence that 60M blocks were filling during demand spikes
The Solana Foundation said 11.2% of blocks produced between the July 22, 2025 activation of the 60 million CU limit and this upgrade used at least 56 million CUs.
That means roughly one block in nine was close to the old ceiling over the period measured.
The pressure was uneven. Blocks were more likely to fill during volatile market periods, when users were also most sensitive to whether trades and other transactions landed promptly.
Raising the cap gives the network headroom for those bursts. If demand is distributed across accounts, a leader can now pack substantially more work into a block before reaching the network-wide limit.
The official material says a smaller increase to 80 million CUs was considered. The network instead moved directly to 100 million after validator-client performance improvements created enough headroom for the larger step.
4. What payment and trading users may notice
The clearest benefit should appear when several applications are busy at the same time.
Before the upgrade, a surge in one part of the network could compete with otherwise unrelated payment, swap, or application traffic for a 60 million CU budget. The 100 million CU ceiling allows more of that independent activity to coexist in one block.
That can improve capacity for:
- wallet transfers and merchant payments
- decentralized exchange activity
- liquidations and collateral updates during volatile markets
- token issuance and settlement
- consumer applications that submit many transactions at once
The word capacity matters. The upgrade does not set transaction fees, guarantee confirmation for a poorly constructed transaction, or eliminate contention around a popular writable account.
Users can still encounter failed or delayed transactions because of application design, priority-fee settings, RPC performance, account contention, or a service outage outside the base network.
5. Validator and infrastructure readiness remains the main operational test
Larger blocks contain more work and can take longer to execute, propagate, replay, and index.
The Solana Foundation identified XDP, a kernel-bypass networking technology, as a key readiness improvement. Its upgrade page said more than 70% of mainnet stake had enabled XDP before the 100 million CU activation. XDP is available in Agave 4.0.0 and later and is enabled by default in Firedancer, according to the same source.
That preparation reduces network-packet overhead, but it does not erase the operational cost of bigger blocks.
The original SIMD lists two specific risks: slower network progress or catch-up when blocks take longer to execute, and unforeseen problems in infrastructure beyond validators. The Foundation separately advised RPC providers, indexers, and exchanges to verify that their systems can handle sustained 100 million CU blocks even though data formats did not change.
Those systems are now the important checkpoint. A successful feature activation proves that the new limit is live. It does not yet prove how every downstream service will behave through prolonged periods of full-capacity traffic.
6. This is a throughput change, not a new security or fee model
The July 29 activation is narrower than several other types of blockchain upgrade.
It does not introduce a new consensus mechanism, change Solana's fee market, shorten slot times, or increase the 12 million CU writable-account limit. The Foundation also says the change is not breaking for developers and does not require indexing-format changes.
What changed is one core ceiling: the total compute a validator can include in a block.
That narrow scope is important for evaluating the claim. More block compute can support higher throughput at the same slot time, but reliability still depends on validators producing and replaying the larger blocks, network infrastructure distributing them, and applications using the added parallel capacity effectively.
The useful test over the next several weeks is not a headline transaction-per-second figure. It is whether the network and its service providers remain stable when demand repeatedly approaches the new limit.
What happened on the key dates
| Event | Exact date | What was confirmed |
|---|---|---|
| Previous 60M CU limit activated | July 22, 2025 | Solana's earlier block-capacity increase moved the network from 50 million to 60 million CUs |
| Upgrade coverage highlighted the final schedule | July 28, 2026 | Broader ecosystem coverage identified epoch 1009 as the planned activation point for SIMD-0286 |
| 100M CU limit activated on mainnet | July 29, 2026 | The Solana Foundation marked the feature live at epoch 1009, raising maximum block compute by 66% |
Why this matters for KrptoPay users
- more aggregate block capacity can give payments and trades additional room during demand spikes
- one congested account can still hit the unchanged 12 million CU writable-account limit
- a capacity increase does not guarantee lower fees or successful confirmation for every transaction
- RPC, exchange, wallet, and indexing performance remains part of the user experience
- sustained high-demand periods will provide stronger evidence than the activation event alone
Frequently asked questions
Q: What changed on Solana on July 29, 2026?
A: Solana activated a higher mainnet block compute limit at epoch 1009. Validators can now include up to 100 million compute units of work in a block, up from 60 million.
Q: Does 100 million CUs mean 100 million transactions per block?
A: No. Compute units measure processing work. The number of transactions in a block depends on how much compute each transaction uses.
Q: Will the upgrade make every Solana transaction cheaper?
A: Not necessarily. The upgrade increases aggregate capacity, but fees and confirmation outcomes also depend on demand, priority fees, account contention, application behavior, and supporting infrastructure.
Q: Can one popular application use the entire larger block?
A: The maximum writable-account limit remains 12 million CUs. A hot account can still become congested, but it now occupies a smaller share of the total block budget.
Q: What should users watch after activation?
A: Watch network stability, transaction landing during volatile periods, RPC and exchange performance, and whether blocks repeatedly approach the new 100 million CU ceiling without replay or catch-up problems.
Sources
- Solana Foundation: 100M CU Blocks, mainnet activation confirmed July 29, 2026
- Solana Improvement Document 0286: Increase Block Limits to 100M CUs
- Solana documentation: Compute Budget, accessed July 29, 2026
- Solana Compass coverage of the epoch 1009 activation schedule, published July 28, 2026
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