Skip to main content

Benchmark numbers only mean something when the measured job is named.

Someone asks whether a cold disk fetch, local warm read, and network command can be compared as one “database speed” number. They cannot. The path label is part of the claim.
Warm

The needed local pages are available and the read shape is known.

Cold

The machine still has storage or setup work before bytes are ready.

Network

The request crosses a network before the app sees the result.

The guardrail is simple: do not silently convert one benchmark category into another.

The categories

Warm local read = the needed data is already local, the operating system already has the needed file pages ready, and Bitfield has the read address.Cold local read = the data is local, but the machine still has setup or fetch work to do before the bytes are ready.Content address lookup = Bitfield first resolves the content identity, then reads the bytes.Durable batch write = Bitfield records a batch of writes in the durable write path, then the benchmark divides the batch cost across the written items.Runtime call = app code asks a Bitfield target to do work through Runtime Kit.Network command = a request crosses the network before the app gets an answer.

Why the split matters

These jobs are different:
JobWhat is includedWhat is not included
Warm local readLocal bytes, warm pages, known read shape.Cold disk fetch, network trip, general database request.
Cold local readLocal storage fetch or setup work.Network trip unless the benchmark says network.
Content address lookupIdentity resolution before reading.Exact-position read with no lookup.
Durable batch writeSaved-write work for a batch.One isolated write measured as its own wall-clock event.
Runtime callRuntime Kit request and reply shape.Raw storage read cost by itself.
Network commandThe networked command path.Local read path by itself.
If a row says one category, read it as that category. Do not silently turn it into another job.

The current public rows

Warm local read.The data is local and warm, so Bitfield can read known local bytes without sending a request to a separate database process.
Content address lookup.Bitfield first resolves the data fingerprint, then reads the bytes.
Durable batch write.The measured work includes the saved-write contract for a batch, then divides the batch cost across written items.
Batched write ceiling.This is a ceiling number for a full batch. It is not the same thing as every saved write.

The rule

The number is allowed to be shocking. The category is not allowed to be blurry.Every public speed claim needs the number, unit, measured category, mechanism, and non-claims. If any of those are missing, the number is not ready for public docs.

Common failures

FailureWhy it is wrongFix
Treating warm and cold as the same pathCache/setup state changes the workLabel warm and cold separately
Comparing local to network without saying soNetwork adds a different jobUse network-command category
Reading batch as isolated writeBatch rows divide work across itemsKeep batch wording visible
Calling lookup the same as exact readLookup includes identity resolutionCompare lookup to lookup

Next

Use Benchmark ledger for current rows and Comparison guardrails before comparing to another system.
Last modified on May 10, 2026