# tempo (/docs/hyperparameters/tempo)

`tempo` is the number of 12-second blocks between a subnet's consensus
epochs. It sets the payout cadence for everyone on the subnet: miners and
validators are paid once per tempo, not per block.

## How it works [#how-it-works]

Each subnet's epoch fires once `tempo` blocks have passed since its last
epoch: `should_run_epoch` (`pallets/subtensor/src/coinbase/run_coinbase.rs`)
checks `current_block − LastEpochBlock ≥ tempo`. The default is 360 blocks
(\~72 minutes); at most 2 subnet epochs run per block, with extras deferred,
and the owner can trigger an early epoch. When the epoch fires, the alpha
accumulated since the previous epoch is distributed via
[Yuma Consensus](/docs/concepts/emissions#yuma-consensus); see
[Epochs](/docs/concepts/emissions#epochs) for scheduling details.

`tempo` also anchors other parameters: the effective
[`activity_cutoff`](/docs/hyperparameters/activity-cutoff) is a per-mille
factor multiplied by `tempo`, and commit-reveal delays are counted in tempos.
Setting a new tempo resets the epoch cycle (`apply_tempo_with_cycle_reset`
re-anchors `LastEpochBlock` to the current block), so the next epoch lands a
full tempo after the change.

The timeline below shows emission accruing block by block and paying out at
each epoch boundary — slide `tempo` across the full owner-settable range
(360 to 50,400 blocks, \~72 minutes to \~7 days) to see the cadence in
wall-clock time.

<HyperparamTempoTimeline />

## Reading and setting [#reading-and-setting]

Inspect with:

```
btcli sudo get --netuid N --name tempo
```

Owner-settable:

```
btcli sudo set --netuid N --name tempo --value 720
```

This dispatches `sudo_set_tempo` (AdminUtils), which is owner-or-root: the
owner is bounded to 360–50,400 blocks (\~72 minutes to \~7 days) and
rate-limited to one change per 360 blocks; root may set any u16. Both paths
respect the admin freeze window, and a successful change resets the epoch
cycle so the next epoch lands a full new tempo after the change.

## Related [#related]

[`rho`](/docs/hyperparameters/rho) ·
[`kappa`](/docs/hyperparameters/kappa) ·
[`activity_cutoff_factor`](/docs/hyperparameters/activity-cutoff-factor) ·
[`max_validators`](/docs/hyperparameters/max-validators) ·
[`commit_reveal_period`](/docs/hyperparameters/commit-reveal-period)