PostTrainBench v1.2 D

AI benchmark · Coding

Domains
Coding
Tier
D why
Snapshot

Open benchmark ↗posttrainbench.com/

What is PostTrainBench v1.2?

PostTrainBench v1.2 measures how well AI agents can post-train small base language models on one H100 GPU in 10 hours, scoring the resulting models across six weighted benchmarks.

Lineage

Benchmarks this one is built on and built from: versions, subsets, extensions and the indexes that combine them.

Built on

Tier D

D

Long tail: little or no usage data yet.

How much stands behind a tier: usage, who backs it, a confirmed line from its own site or paper, and a clear read on X. High with three of the four, medium with two, low otherwise.

  • no usage data
  • in curated RL directories (1 pt)

On X · unclear, low buzz, from 3 posts about PostTrainBench v1.2 in the last month

The v1.2 release posts note a new leaderboard led by Fable 5.1, Harbor/Modal cloud support and evaluation fixes; there is little outside discussion.

@hrdkbhatnagar ↗ · @thoughtfullab ↗ · @Bayesian0_0 ↗

How we got to tier D
  1. Adoption: no usage data. Tier D.
  2. On X: unclear, low buzz. “The v1.2 release posts note a new leaderboard led by Fable 5.1, Harbor/Modal cloud support and evaluation fixes; there is little outside discussion.” No move.
  3. In curated RL directories: 1 point, a floor of none.
  4. Confirmed: a line from its own site or paper places it.

A clear view on X moves a tier one step up or down; most entries don't move. How tiers work.

Where PostTrainBench v1.2 sits

Its domain on the map, live. Hover a logo for its name; click to open it. Open it on the full map

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Next: browse all benchmarks. Entry from the RL Research daily scrape of public sources, 2026-10-29 snapshot.