Theoretical Maximum Storage for Auto Drive
Current Network Capacity
Based on the chain specification in the Autonomys Subspace repository, here are the key parameters:
- Total Network Pledged Space: 158 PiB (162,201.6 TB)
- Replication Factor: 25x (defined in chain spec)
- Theoretical Maximum Usable Storage: ~6.34 PiB (6,488 TB)
Source Code Reference
Found in subspace_repo/crates/subspace-runtime-primitives/src/lib.rs:35-37:
/// Minimum desired number of replicas of the blockchain to be stored by the network,
/// impacts storage fees.
pub const MIN_REPLICATION_FACTOR: u16 = 25;
Calculation
Effective Storage = Total Pledged Space ÷ Replication Factor
= 158 PiB ÷ 25
= 6.34 PiB (6,488 TB)
This means that out of 158 PiB total network capacity, approximately 6.34 PiB is theoretically available for actual user data storage, with the remainder used for 25x redundancy to ensure data reliability.
What Happens When Storage Fills Up?
The network uses a dynamic pricing mechanism to handle capacity constraints. The storage fee formula (from pallet-transaction-fees/src/lib.rs):
pub fn calculate_transaction_byte_fee() -> BalanceOf<T> {
let credit_supply = T::CreditSupply::get();
match (T::TotalSpacePledged::get() / u128::from(T::MinReplicationFactor::get()))
.checked_sub(T::BlockchainHistorySize::get())
{
Some(free_space) if free_space > 0 => {
credit_supply / BalanceOf::<T>::saturated_from(free_space)
}
_ => credit_supply,
}
}
Key Behavior
As the network fills up:
- Available storage decreases → denominator in the formula gets smaller
- Storage costs increase proportionally → higher fees per byte
- Economic incentive created → farmers are incentivized to add more storage capacity when demand is high
- Network naturally expands → the system is designed to scale as needed
The formula ensures that:
storage_fee_per_byte = total_credit_supply / ((total_space_pledged / min_replication_factor) - history_size)
As storage approaches capacity, fees rise automatically, creating market pressure for expansion.
Free Storage Allocation & Pricing
The current free storage allocations on ai3.storage are sponsored by the Subspace Foundation as a grant that renews monthly. This initial free tier allows users to experience the service, but is not guaranteed to be a permanent fixture.
The team is actively working on a direct purchase mechanism that will enable users to buy storage on ai3.storage. This represents the only sustainable path forward, ensuring:
- Users pay for their own storage needs
- The Foundation’s grant program isn’t drained by sybil attacks (users creating multiple wallet accounts to abuse free allocations)
- Long-term viability of the storage service
In short: Current free tier = temporary Foundation grant. Future model = user-paid storage purchases.