# Nemotron 3 Ultra 550B on the Cotera agent benchmark

> Biggest and priciest Nemotron, worst value — 1/5 at $2.46, most of it burned looping.

Source: https://cotera.co/benchmarks/models/nemotron-3-ultra-550b

---

NVIDIA's Nemotron 3 Ultra, a 550B open MoE (55B active), run through OpenRouter. The flagship of the Nemotron 3 line.

**Score:** 1/5 benchmarks passed · **Cost across the matrix:** $2.46

## Strengths
- Did pass the coding benchmark once the tool-call middleware let its calls through — a competent HMAC-SHA256 verifier over 15 tool calls.
- Large 1M context and strong raw reasoning on paper.

## Watch-outs
- By far the most expensive model in this suite: $2.46 for a single pass. One Reddit run alone burned ~$1.73 across 25 tool calls and still produced no valid JSON.
- Most fragile tool-caller of the family — repeatedly emitted tool calls as plain text, which without the repair middleware ends the agent loop with no answer.
- Inconsistent final output: malformed or missing JSON on four of five benchmarks, plus one run that dropped a required field.