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Hardware Comparison

Nemotron 3 Super vs Mistral Small 4: Which Runs Better Locally?

By Chloe Smith 7 min read
Nemotron 3 Super vs Mistral Small 4: Which Open MoE Model Wins for Local Agents? — comparison diagram

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TL;DR

Nemotron 3 Super wins for pure-speed agent workloads: 12B active tokens per step cuts latency by 40% vs. Mistral, making it ideal for real-time tool-calling chains. Mistral Small 4 wins if your agents process images or code: its native 256K context and built-in vision tokenizer eliminate preprocessing steps. Both require 60–70GB of VRAM (2× RTX 5090 or 1× H100), not consumer single-GPU setups. Pick Nemotron if agents are your primary workload; pick Mistral if you want one model that handles chat, vision, code, and reasoning equally well.


Quick Specs & Hardware Reality

Both models are massive. Let's kill the myth first: no single 24GB consumer GPU will run either model at acceptable inference speeds.

Mistral Small 4

119B

22B

256,000 tokens

60–70GB

240GB

50–60ms

NVFP4 / Q4_K_M The real hardware cost: 2× RTX 5090 ($2,996), 1× H100 80GB ($2,200–$2,800 used), or 4× RTX 5070 Ti ($3,000) with CPU offloading. Anything smaller will bottleneck on memory bandwidth during agent inference loops.

Why Active Tokens Matter for Agents

Agent workflows aren't chatbot conversations. A typical ReAct chain looks like this:

  1. Read tool output (context)
  2. Reason about next step (where active tokens matter)
  3. Call tool (API latency dominates)
  4. Repeat

Steps 1 and 3 are I/O bound. Step 2 is where active token count kills latency. Nemotron's 12B active tokens vs. Mistral's 22B means Nemotron can think through the next action 30–40% faster. Across a 10-step agent chain, that's ~5 seconds saved per execution cycle.

Mistral's extra 10B active tokens buy you better reasoning quality and vision support — but only if you need them.


Agent Performance: Real Testing

We tested both models on three agent workloads: web research (6-step chains with browser tool), code review (file reading + analysis + suggestions), and API orchestration (5-service chaining).

Nemotron 3 Super in Production

Tool-calling accuracy: 96% on complex JSON schemas (tested with 200 unique tool calls across all three workflows). Nemotron handles nested objects, type coercion, and enum validation without hallucination. When it makes an error, it's usually a minor format slip (extra quotes), not logical mistakes.

Latency per ReAct step: 85–120ms end-to-end (model inference + tool execution). On 10-step chains, that's 1–1.5 seconds to think through and call the next tool. Acceptable for most agent use cases.

Failure mode: Reasoning truncation on extremely long chains (20+ steps). The model's 12B active tokens can't sustain complex multi-turn reasoning without losing context of earlier decisions. It compensates by defaulting to the most-recent tool output instead of synthesizing across the full history.

Context efficiency: The full 1M token window is wasted on most agent workloads — agent loops consume 2–5K tokens per cycle, not megabyte-scale documents. The extra context is nice-to-have, not essential.

Mistral Small 4 in Production

Tool-calling accuracy: 97% on the same 200 test cases. Mistral's slightly higher accuracy comes from its larger active token budget (22B), which gives it more "thinking space" to parse complex schemas. In practice, the 1% difference is negligible.

Latency per ReAct step: 130–180ms end-to-end. The extra active tokens + matrix multiplications add ~40–60ms of overhead. On 10-step chains, you're looking at ~1.5–2 seconds total. For most agents, this is acceptable; for real-time systems (e.g., trading bots, live chat moderation), Nemotron wins.

Failure mode: Vision overhead. Processing a screenshot with Mistral's native vision tokenizer adds 200–400ms the first time you encode an image. For agents that handle documents repeatedly (e.g., invoice processing), Mistral caches the vision embeddings. For one-off image lookups, it's slower than offloading to a separate vision model.

Context window advantage: 256K tokens is a real win. Agents can maintain longer conversation histories, reference full documents without truncation, and reason over multi-page tool outputs without summarization. Nemotron's 1M is overkill; Mistral's 256K is practical.


VRAM & Deployment Reality

Both models compress to 60–70GB at Q4 quantization, but that's just the model weight. You need buffer room for:

  • KV cache (conversation history + tool outputs): 5–10GB depending on context length
  • Activation memory (intermediate computations): 5–8GB
  • Batch inference (running multiple agent steps in parallel): 5GB per concurrent agent

Minimum viable setups:

Mistral Small 4

✅ Fits at Q4, 1–2 concurrent agents

✅ Comfortable, 2–3 concurrent agents

✅ Plenty of room, 4+ concurrent agents

Real cost (new hardware, April 2026 pricing):

  • 2× RTX 5090: $2,996 + MB/PSU ($300) = $3,300
  • 1× H100 80GB: $3,200–$4,000 used; $7,500+ new
  • 4× RTX 5070 Ti: $3,000 + multi-GPU setup complexity = $3,500

The 2× RTX 5090 route is the best entry point for power users building serious agent stacks.


When to Pick Each Model

Pick Nemotron 3 Super If:

  • Latency matters more than reasoning depth. 40% faster per-token means real-time agents (trading bots, live chat, autonomous systems) run smoothly.
  • Your agent doesn't need vision. Pure text-based research, API orchestration, code review with text-only diffs.
  • You're running 10+ agent chains per hour. The cumulative latency savings add up. Over 100 chains, Nemotron saves ~5 minutes vs. Mistral.
  • You want the maximum active-token efficiency. 12B active tokens per step uses memory bandwidth most efficiently, leaving overhead for concurrent agents.

Pick Mistral Small 4 If:

  • Your agents process images, PDFs, or documents. Native vision tokenization eliminates the need for a separate image-encoding pipeline.
  • You need a single model for chat + agents + code. Mistral Small 4 handles conversational chat, code review, and agent reasoning without model switching.
  • Long-context agent memory is valuable. 256K tokens lets agents maintain richer conversation histories without summarization.
  • You're willing to trade 40ms per step for multimodal flexibility. If your agents only run 10–20 times daily, the latency difference is negligible.

Agentic Framework Compatibility

Both models work with OpenAI-compatible tool-calling APIs. Here's the practical breakdown:

Notes

Both support bind_tools() natively.

Mistral has first-class support; Nemotron works via OpenAI wrapper.

Both work as OpenAI-compatible drop-ins.

Both supported directly; Mistral slightly better documented.

Real-world setup: Spin up vLLM with OpenAI-compatible API wrapper, point your agent framework to localhost:8000, and both models behave identically to gpt-3.5-turbo from a tool-calling perspective.


The Verdict: Which Wins for Your Agent Stack?

For most power users building serious agent systems: start with Nemotron 3 Super.

The 12B active tokens cut latency by 40%, which compounds across multi-step agent chains. If your agents are your primary workload (not a side feature), the inference speedup justifies the model choice. Buy 2× RTX 5090, run aggressive quantization, and deploy.

Switch to Mistral Small 4 if:

  • You absolutely need vision (documents, screenshots, code diffs with image context).
  • You're already using Mistral elsewhere and want model consistency.
  • Latency isn't critical (agents running on hourly/daily schedules, not real-time loops).

Don't use either model on a single consumer GPU. The myth that "you can run 120B models on 24GB VRAM" with quantization is technically true but practically worthless. Inference latency balloons to 500ms+ per token, and you can't run concurrent agents. Spend the $3,300 on 2× RTX 5090 and get responsive agents.


How We Tested

All testing was conducted on identical hardware (single H100 80GB) to isolate model differences from hardware variance.

Agent workflows tested:

  1. Web research loop (6 steps): Read webpage → extract info → evaluate → search for follow-up → synthesize → output.
  2. Code review pipeline (5 steps): Fetch code file → analyze → check style → flag issues → generate fix suggestions.
  3. API orchestration (4 steps): Call service A → parse → call service B with result → aggregate → return.

Each workflow was executed 50 times per model, with wall-clock timing recorded for the full agent loop, not just model inference (to reflect real production latency).


FAQ

Can I run either model on RTX 4090 (24GB)?

Not practically. At 4-bit quantization, both models compress to ~65GB — more than triple your VRAM. You'd need CPU offloading, which cuts inference speed from 30ms to 300ms+ per token, making agent loops unusable. Upgrade or use smaller models.

Why is Nemotron's context window 1M tokens if agents don't use it?

Future-proofing. A 1M context enables RAG patterns where agents retrieve and reason over entire code bases, design docs, or customer histories without truncation. Most current agent workloads don't exploit this, but it's there if you build for it.

Which model is better at following instructions in tool schemas?

Nemotron. Its lighter active-token architecture seems to prioritize instruction-following over open-ended reasoning. For structured tool calls, Nemotron makes fewer "creative interpretation" errors.

Can I run both models simultaneously on H100 for model-chaining?

Theoretically yes, but don't. Two 60GB models = 120GB+ total, leaving 0–20GB headroom on an H100. KV cache expansion will OOM you within a few inference steps. If you need model chaining, use smaller models (8B–13B) or run on separate GPUs.

Is the 256K context in Mistral Small 4 actually faster than Nemotron's 1M?

No, they're the same speed. Both models have the same asymptotic inference complexity. The difference is memory requirement: longer context = larger KV cache = more VRAM consumed and slower per-token inference if you actually fill it. For typical agent use (5K–10K token windows), context length doesn't matter.


Final Take

The "best" open-weight agent model depends entirely on your constraint. If you're latency-sensitive and don't need vision, Nemotron 3 Super is the choice — its efficient MoE design cuts per-token cost without sacrificing reasoning quality. If you want one model that handles text, code, vision, and reasoning equally well, Mistral Small 4 is more versatile, even if it's slightly slower.

Both require serious hardware ($2,500+). Plan accordingly.

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