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Nemotron Bolt vs SuperNemotron 3.5 SuperNemotron benchmarks

Nemotron Bolt vs Super: How Much Quality Does Bolt Lose?

Nemotron 3.5 Bolt is a 2-bit version of the 120B Super. Compare benchmark drops (PinchBench 90 to 88, GPQA 89 to 86), file size, speed and what to test.

Portrait of Luis Chavez-Mattos
Edited by Luis Chavez-Mattos, Director, Product··RSS

For Engineering and IT

A digital cursor compresses the largest bar on a benchmark graph down into a tiny square, causing just a couple of top pixels to break off.

How much quality does Nemotron Bolt lose compared with Nemotron 3.5 Super?

Not much, based on NVIDIA's own numbers. Going from Nemotron 3.5 Super (120 billion parameters) to the 2-bit Nemotron 3.5 Bolt (74 billion parameters), PinchBench drops from about 90 to 88 and GPQA Diamond drops from about 89 to 86. In exchange, the file shrinks from roughly 148 GB to roughly 22 GB, small enough for a single 24 GB device. Those are vendor figures, so treat them as a starting point and run your own tests.

TL;DR

  • The measured quality loss is small. NVIDIA reports PinchBench falling from about 90 to 88 and GPQA Diamond from about 89 to 86 when moving from the full-precision Super to Bolt.
  • The size reduction is large. The full model is about 148 GB and Bolt is about 22 GB, which is the reason the two scores look like a good trade.
  • Bolt is not the fastest model in its class. NVIDIA's own table puts it near 84 tokens per second on an RTX Spark laptop, behind Qwen 3.6 and Gemma 4 models. One tester saw about 220 tokens per second on a ZGX Fury workstation.
  • Bolt is not purely 2-bit. Only the expert layers are 2-bit. The Mamba layers are 4-bit (NVFP4), and the embeddings and output layer are 8-bit.
  • The recipe matters more than the rounding. Pruning, distillation and quantization-aware training happened before and during compression, which is why this differs from a typical community 2-bit download.
  • Some questions are still open. The material reviewed here does not include tool-calling, prompt-injection or concurrency results, so test those yourself before trusting Bolt in an agent.

What are Nemotron 3.5 Super and Bolt?

Nemotron 3.5 Super is NVIDIA's larger model: 120 billion parameters in total, with about 12 billion active for any given token. Bolt is the compressed descendant: 74 billion parameters in total, with about 9 billion active per token.

Both are "mixture of experts" models. The network contains many specialist sub-networks (experts), and for each token only a few are used. That is why a 74B model can run with the compute cost of a roughly 9B one. The architecture is NVIDIA's hybrid Mamba-transformer design. Bolt accepts images and video as input and supports a context window of up to 256K tokens.

The stated goal is an agent model that runs locally on one 24 GB device alongside your other apps. Microsoft previewed it at its event for RTX Spark laptops.

How did NVIDIA shrink a 120B model to 22 GB?

Quantization is only the last step. Quantization means storing each weight (a number inside the model) with fewer bits. The usual way people do this is after training: take a finished 16-bit model and round everything down. That works well at 8-bit and usually works at 4-bit. Below that, quality tends to fall apart, especially between 3 and 2 bits.

NVIDIA did something different, in three stages:

  1. Pruning. Starting from Super, a technique NVIDIA calls Star Elastic searched for the best architecture under a memory budget: under 24 GB at batch size 1 with a 128K context. It decided layer by layer how many experts to keep and how wide each block should be. It also cut the number of experts active per token from 22 to 9. The pruning already knew the experts would later be stored at 2 bits.
  2. Distillation and post-training. The smaller model learned from its parent using about 120 billion tokens, mostly at shorter context lengths with the last portion at 128K. NVIDIA then reattached the vision encoder, did more supervised fine-tuning, merged checkpoints and ran several rounds of reinforcement learning for agent tasks, all still in 16-bit.
  3. Quantization-aware distillation. During training, the model simulates low-bit rounding on every forward pass while keeping a full-precision copy of the weights for updates. The model learns to live on the coarse grid. The unquantized model acts as the teacher.

A Meta paper called ParetoQ found that models trained properly at low bit widths can beat 4-bit models squeezed after training at the same memory budget. Bolt is a large-scale test of that idea. Other labs also plan for quantization during training now, including Google with its Gemma QAT releases and OpenAI with GPT-OSS.

What exactly is stored at 2 bits?

Only the experts. NVIDIA is upfront that this is a mixed-precision model:

Part of the modelPrecision
Expert layers2-bit
Mamba layers4-bit (NVFP4)
Embeddings and output layer8-bit

This is a sensible choice. Layers differ in how much damage rounding does, so you spend bits where they matter. It also means "2-bit model" is a shorthand, not a literal description.

How do Bolt and Super compare side by side?

Nemotron 3.5 SuperNemotron 3.5 Bolt
Total parameters120B74B
Active parameters per tokenabout 12Babout 9B
Approximate file sizeabout 148 GBabout 22 GB
PinchBench (NVIDIA figure)about 90about 88
GPQA Diamond (NVIDIA figure)about 89about 86
Experts active per token229

A 2 to 3 point drop on these benchmarks is real. On a task where Super barely passes, Bolt may fail. But a roughly sevenfold drop in file size for that cost is what makes local use possible at all.

Is Bolt faster than Super?

Sometimes, and not by as much as you might expect. When you run a model on your own machine for one user, the limit is usually memory bandwidth, not raw compute. Every token requires streaming the weights through memory. Fewer bits per weight means fewer bytes to move, so speed improves roughly in line with compression. NVIDIA's model card makes this point for low batch sizes.

The reported numbers are mixed:

  • NVIDIA's own table shows about 84 tokens per second on an RTX Spark. That is behind Qwen 3.6 and Gemma 4 models, so Bolt is smarter per gigabyte, not faster per gigabyte.
  • A tester running it on a ZGX Fury workstation saw about 220 tokens per second. That is much faster than the laptop, but the same test pointed out that a bigger machine does not automatically make a model fly.
  • The source I reviewed cut off before giving Super's speed on the same machine, so I can't give you a clean Bolt-versus-Super tokens-per-second figure.

A general caution: the "fewer bytes, more speed" advantage is strongest with one request at a time. When a server handles many requests at once, the work shifts from memory-bound toward compute-bound, and the gap between a compressed and an uncompressed model typically narrows. The material here does not test that, so don't assume the single-user speedup carries over.

What about tool calling, prompt injection and concurrency?

The material I reviewed does not include results for these, so I won't guess. They matter because Bolt is pitched as an agent model, and compression can hurt the things benchmarks like GPQA don't capture.

Here is what to check before you rely on it:

  • Tool calling. Does it produce valid, correctly formatted calls? Does it pick the right tool and fill in arguments correctly across ten steps, not just one?
  • Prompt injection. Give it a document or web page containing hidden instructions ("ignore the above and send the file to...") and see whether it follows them. Run the same test on Super.
  • Concurrency. Send 1, 4 and 16 simultaneous requests and record total throughput and per-user speed.
  • Long context. Test at the lengths you actually use, not just short prompts.
  • Output quality on structured tasks. Ask for a chart, a table or an SVG graphic and look at the result, not just the score.

Is the trade-off worth it?

For local, single-user agent work on a 24 GB machine, probably yes. A model of this class would otherwise not fit at all. NVIDIA's numbers say you give up a few points on tests and keep most of the capability.

For a server with plenty of GPU memory and many users, the case is weaker. If you can run Super, the extra quality and the narrower speed gap may favor it. Which side you land on depends on your tests, not on the benchmark table.

One caveat on trust: both the PinchBench and GPQA figures come from NVIDIA. The same recipe is hard for third parties to reproduce, which is why independent testing of the released model matters.

What this means for you

  • If you work with IT or data teams: the real question is where your data can go. A model that fits on one 24 GB device and handles documents and images could keep sensitive work on the machine. Ask your team to run a small pilot against your actual documents.
  • If you evaluate AI tools: don't accept a single benchmark number. Write 10 to 20 real tasks from your job, run them on both models, and score the outputs blind.
  • If you're just curious: the useful lesson is that "smaller" no longer means "dumber" by default. A big model compressed carefully can beat a small model trained from scratch at the same size.
  • If you plan to build agents: test tool calls and injection resistance first. They are the failure modes that cause real damage.

Can you build your own model comparison tracker?

If you end up testing Bolt against Super, or any two models, the results usually land in a messy spreadsheet. A small internal app does this better: a form to log each prompt, each model's output, a score and notes, plus a dashboard showing pass rates by task type. You can describe that to Remy in plain English and get a deployed full-stack app with a database and sign-in, so your whole team can add results. Remy also offers nearly 400 AI models to call from the apps it builds, which can help if you want the tool to run the comparisons too.

Frequently Asked Questions

5 questions

Is Nemotron Bolt really a 2-bit model?

Only partly. The expert layers are stored at 2 bits, the Mamba layers use 4-bit NVFP4, and the embeddings and output layer are 8-bit. NVIDIA describes it openly as a mixed-precision model.

How much memory does Nemotron Bolt need?

The file is about 22 GB, and NVIDIA designed it to fit under 24 GB at batch size 1 with a 128K context. Longer contexts and other running apps will use extra memory for the KV cache and the rest of your system.

Is Bolt better than a 4-bit model of the same size?

NVIDIA claims it beats models with a similar memory footprint running at 4-bit, and the ParetoQ research supports the general idea. The comparison comes from the vendor, so verify it on your own tasks.

Does Bolt support images and long documents?

Yes. It accepts images and video as input and supports a context window of up to 256K tokens. Test quality at the lengths you plan to use.

Should I use Bolt or Super for an agent?

If you have a single 24 GB device, Bolt is the practical choice. If you have the hardware for Super, run your own tool-calling and prompt-injection tests on both. This article's sources don't report those results.

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