What are compute units?

Every instruction a Solana program runs costs compute units, roughly what gas is on EVM chains. A plain SOL transfer needs about 150. A multi-hop swap can use several hundred thousand. If a transaction does not ask for a limit, each program instruction gets up to 200,000 units by default (built-in ones like a SOL transfer get 3,000), and no transaction can go past 1.4 million.

You set an explicit limit with the Compute Budget program. A tight limit helps twice. The priority fee is charged on the requested limit, so a padded limit overpays. And each block has a total compute budget, so a smaller request is easier for the scheduler to fit in.

Take a made-up swap that really uses 140,000 units. It requests a padded limit of 200,000 at 50,000 micro-lamports per unit and pays 10,000 lamports of priority fee. With the limit set to 150,000, the same price costs 7,500 lamports. Same priority, 25 percent cheaper.

Run out of units halfway and the transaction fails. It still pays its fees. That is why wallets simulate a transaction first, measure what it used and add a small buffer before sending.

Also called: CU, compute budget.

Cashboard does not show compute units for individual transactions. It shows the price side: Chain status gives Solana's median priority fee in micro-lamports per compute unit, and Solana pulse turns its fee tiers into the cost of a 200,000 CU transaction plus the 5,000-lamport base fee.

• Chain status
• Solana pulse

• Official sitesolana.com
• Official documentationsolana.com

• Solana priority fees
• Lamports
• Gas fees
• Jito tips