Hyperparameters
burn_increase_mult
Shared multiplier for independent burn price and PoW difficulty increases.
This historical parameter name controls both burn price and PoW difficulty. A successful burn registration increases only burn cost; a successful PoW registration increases only PoW difficulty. Each route has its own demand signal, while both reuse this multiplier. No TAO is charged by the PoW path, and failed registrations do not change either price.
Controls how sharply the registration price reacts to demand: every successful burn registration multiplies the current burn cost by this factor. Owners tune it to decide how strongly a registration burst should price out the next entrant; miners see it as the reason the cost quoted a moment ago can jump before their own transaction lands.
How it works
After each successful burn registration,
bump_registration_price_after_registration
(in pallets/subtensor/src/subnets/registration.rs) sets
new_burn = clamp(burn × burn_increase_mult, min_burn, max_burn)The bump is immediate — the next burn registration, even in the same block,
pays the raised burn price. PoW registrations apply the same calculation to
difficulty, bounded by min_difficulty and max_difficulty, and do not raise
burn cost. Values below 1 are treated as 1 at read time
(max(mult, 1)), so the multiplier can never shrink the price. Between
registrations, the per-block decay governed by
burn_half_life pulls the price back
toward min_burn. The steady-state
registration rate the pair supports is where bumps and decay cancel:
half_life × log2(mult) blocks per registration.
The value is stored in
BurnIncreaseMult as U64F64
fixed-point (raw bits
divided by 2^64 give the real multiplier); the default is 1.26 (~3
registrations to double the price). The owner-set extrinsic
(sudo_set_burn_increase_mult
in pallets/admin-utils/src/lib.rs) requires
the value to be between 1 and 3 inclusive and rejects the root subnet,
which does not use the bump path.
A burst of 8 registrations, one every 30 blocks (~6 min): each multiplies the price by burn_increase_mult, stacking into a staircase that the half-life decay then unwinds. Drag the multiplier to steepen or flatten the stairs.
Peak in window
τ0.378
After ~4.8h
τ0.0397
Break-even rate
60 regs/day
Above this, the price climbs; below it, decay wins.
Reading and setting
btcli sudo get --netuid 12 --name burn_increase_mult
btcli sudo set --netuid 12 --name burn_increase_mult --value 1.5Settable by the subnet owner or root. A value with a decimal point is the
multiplier itself (1.5); a plain integer is the raw U64F64 bits.
Related
burn_half_life— the decay that counteracts these bumpsmin_burn/max_burn— the clamp boundsmax_regs_per_block— the hard per-block cap behind the price mechanism