Solana Proposal Simulation Cuts Validator Handover Latency 53%

A proposed Solana scheduling change would reorder validators by geography to cut block-handover latency under Alpenglow. A companion proposal would require validators to register locations if the system activates, while both proposals require specified reviewer approvals before they can be merged.

Solana Improvement Document SIMD-0675 was marked ready for review at 10:27 a.m. ET (14:27 UTC) on Sept. 30. The open proposal would reorganize the network’s stake-weighted leader schedule so validators in nearby geographic areas produce blocks consecutively.

The change would preserve the number of leadership opportunities assigned to each validator and alter only their sequence. A simulation using epoch 1038 mainnet data from 661 validators reduced mean handover latency from 36.2 milliseconds under the existing schedule to 17.0 milliseconds under the proposed arrangement.

That result represented a 53% reduction in the simulation, not a confirmed performance gain on Solana’s live network. Latency measurements were used for the simulation, while the production algorithm would not use those measurements directly.

The design would place validators into geographic bins and limit consecutive leaders from any one bin to three. A complete scheduling run is estimated to take about 2.4 seconds. The proposal would also increase HANDOVER_COMPENSATION from 25 milliseconds to 50 milliseconds.

The scheduling change is intended for Solana’s Alpenglow consensus system, which targets faster transaction finality. Solana activated Alpenglow on public testnet and devnet last week.

SIMD-0675 depends on SIMD-0180, which defines Solana’s base leader schedule, and SIMD-0630, which defines handover compensation.

A companion proposal, SIMD-0674, would add validator location data to vote accounts using a 12-byte Earth-centered, Earth-fixed coordinate triple. Validators would submit their own coordinates, while validation checks would confirm the geometry without establishing whether the coordinates match their physical locations.

If SIMD-0674 activates, validators without registered locations would be excluded from block production and voting. Both proposals require approval from at least one Anza reviewer and one Firedancer reviewer before they can be merged.

Neither proposal had received those approvals or been approved, merged or activated as of Sept. 30. No activation timeline was stated.