Bittensor Adds Optional Mode That Raises Subnet Capacity to 2,500

Bittensor’s Runtime 475 adds an optional way for subnet owners to expand registration capacity, while giving one identifier control of the scores used to calculate miner rewards. The change offers room for more registered participants but concentrates scoring authority in the highest-stake-weight validator.

Released Oct. 7 at 4:40 p.m. ET (20:40 UTC), Runtime 475 introduced Null Consensus. Subnets stay on Yuma by default, including newly created subnets. An owner must select Null and separately increase the subnet’s configured capacity for the higher limit to apply.

Under Yuma, multiple eligible validators contribute scores. Null accepts miner-weight submissions from only the registered identifier with the highest stake weight. The mode also bypasses Yuma’s consensus and bond calculations.

Null’s 2,500-identifier ceiling applies across a subnet’s emission mechanisms. With one mechanism, the subnet can register up to 2,500 identifiers; with two, the limit is 1,250 per mechanism; with four, it is 625 each. Yuma’s limit is 256. The root network cannot select Null and has separate staking and registration rules.

The scoring restriction does not remove dividend eligibility for other stakers. Every identifier with positive stake remains eligible for a proportional share of validator dividends, including inactive identifiers and those without a validator permit. A person backing a smaller validator can still qualify for dividends even when that validator cannot submit miner scores in a Null subnet. The validator’s take, or the share of staking emissions it keeps before distributing the remainder, affects what nominators receive. Staking TAO on a subnet also converts it into that subnet’s alpha token.

Runtime 475 also lets owners of non-root subnets enable proof-of-work registration under either consensus mode. For a direct registration with no tip, the route requires computing work and removes the need for a TAO registration burn, an initial collateral purchase and a transaction fee. The setting is off by default.

Owners switching a Null subnet back to Yuma must first bring its registered population down to Yuma’s lower capacity limit. Null’s pruning process can remove no more than 64 identifiers in a single transaction.