Anthropic AI R&D - LLM Training Average Speedup: leaderboard

LLM training task (easy variant) from Anthropic's internal AI R&D rule-out suite: average speedup (x) from optimizing a small language-model training implementation; unbounded, higher is better. From Table 2.3.5.A of the Claude Opus 5 System Card (July 2026); the Sonnet 5 row is from Table 2.3.3.A of the Sonnet 5 card.

Metric: Average Speedup (x). Source: www-cdn.anthropic.com. Saturation forecast: Around March 2028. 4 models tracked.

Top models

#ModelScoreOverall rank
1Claude Mythos 569.61#8
2Claude Opus 568.54#16
3Claude Opus 4.750.67#51
4Claude Sonnet 526.49#65

No result here: #3 Claude Opus 5.5, #6 GPT-6 Astra, #7 GPT-6.1 Sol.

Interactive version: theaggregate.ai/benchmark?slug=anthropic-ai-r-d-llm-training-average-speedup · How It Works · Data refreshed daily, snapshot 2026-11-05.