GPT-5.6 Luna (Xhigh) vs Granite 4.2 3B
Which is better for the money: GPT-5.6 Luna (Xhigh) by OpenAI or Granite 4.2 3B by IBM? Intelligence, total benchmark cost, and end-to-end time from Artificial Analysis & other sources, snapshot 2026-10-27.
Trade-off
Verdict
Depends on your budget
GPT-5.6 Luna (Xhigh) scores 25.5 points higher (34.6 vs 9.1) but costs 12× as much to run the benchmark ($179 vs $14.9; mid-range vs budget cost classes). They are not alternatives at one budget: pick GPT-5.6 Luna (Xhigh) when you need intelligence above 9.1, and Granite 4.2 3B when 9.1 is enough.
| Metric | GPT-5.6 Luna (Xhigh) | Granite 4.2 3B | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 34.6 | 9.1 | −73.7% Granite 4.2 3B is 73.7% less intelligent |
| Total AA cost (lower is better) | $179.33 | $14.91 | −91.7% Granite 4.2 3B is 91.7% cheaper |
| End-to-end time (lower is better) | 45.86s | 62.73s | +36.8% Granite 4.2 3B is 36.8% slower |
| Price per 1M tokens (in / out) | $0.20 / $1.20 | $0.03 / $0.12 | |
| Input modalities | Text, Image | Text |
Granite 4.2 3B vs GPT-5.6 Luna (Xhigh): 73.7% less intelligence, 91.7% less cost to run the AA benchmark, and 36.8% slower end-to-end.
Today's Pareto frontier
Against the frontier
- GPT-5.6 Luna (Xhigh) is off the frontier: at the same or lower cost, GPT-6.1 Terra (Medium) scores 41.30 for $175.
- Granite 4.2 3B is off the frontier: at the same or lower cost, GPT-6 Luna (Low) scores 21.50 for $10.6.
GPT-5.6 Luna (Xhigh)Granite 4.2 3BToday's Pareto frontierOpen-weights frontierEvery other model
Matchup
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