Pulsar 16B
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Optimized for Fast and Efficient Inference · Reduced Memory Footprint
Table of Contents
Model Overview
Pulsar 16B is a model based on NVIDIA-Nemotron-3-Nano-30B-A3B-BF16, developed by Multiverse Computing. The original model is a ~31.6B parameter, part of the Nemotron model family. It supports long-context inference up to 1M tokens and is designed for general-purpose language modeling tasks.
This version applies model compression techniques to significantly reduce parameter count and deployment requirements while maintaining compatibility with the Nemotron Hybrid Mamba2-Transformer with MoE architecture. The resulting model achieves 50% compression, reducing the parameter count to 16.15B parameters and lowering memory requirements.
Key Characteristics
Quick Start
This model can be loaded with the Transformers API. Use trust_remote_code=True. Recommended approach: AutoModelForCausalLM with apply_chat_template. This configuration has been tested with Transformers 4.57.6.
Alternatively you can use the pipeline API with trust_remote_code=True; the pipeline returns the full conversation structure, so extract the assistant message from outputs[0]["generated_text"] as needed.
vLLM Serving
Installation
Reasoning parser (NVIDIA)
Pulsar 16B uses the same Nemotron v3 reasoning tags as the base model. NVIDIA provides the vLLM plugin as nano_v3_reasoning_parser.py on the base Hugging Face repo (not specific to Pulsar). Direct download:
You can keep any local filename; the vllm serve flags below assume the file is in the current directory as nano_v3_reasoning_parser.py. If you mirror an identical copy under the Pulsar model repo, use that URL instead.
Serve
Note: The NeMo container nvcr.io/nvidia/nemo:25.11.nemotron_3_nano comes with mamba_ssm and causal-conv1d pre-installed.
Thinking (Reasoning) Control
Pulsar 16B supports a hybrid reasoning mode: the model can either think step-by-step before answering (reasoning mode) or reply directly (non-reasoning mode). The behaviour is controlled via the enable_thinking flag in the chat template.
This section provides a brief overview of reasoning control in Pulsar 16B. For comprehensive details please see the official Nemotron-3 Nano-30B model card at: https://build.nvidia.com/nvidia/nemotron-3-nano-30b-a3b/modelcard
Transformers API
Pass enable_thinking through apply_chat_template:
Thinking ON (default)
Thinking OFF
When thinking is ON the model opens a <think> block before the answer.
vLLM
Server-level default
Set the default for all requests at startup with --default-chat-template-kwargs.
Requires recent versions of vLLM.
Thinking OFF for all requests
Thinking ON for all requests (default if flag is omitted)
Per-request override
--trust-request-chat-template is required to allow per-request overrides.
Individual requests can override the server default by passing chat_template_kwargs in the request body. This works regardless of the server-level default.
Thinking ON/OFF for one request
Tool Calling
Pulsar 16B emits tool calls in the following format:
When serving (e.g with vLLM), you must use the qwen3_coder tool parser.
Training & Fine-Tuning
Base Model: NVIDIA-Nemotron-3-Nano-30B-A3B-BF16
The base model nvidia/NVIDIA-Nemotron-3-Nano-30B-A3B-BF16 is a large language model (LLM) trained from scratch by NVIDIA, and designed as a unified model for both reasoning and non-reasoning tasks. The model's reasoning capabilities can be configured through a flag in the chat template. See the original model card for details.
CompactifAI Compression
CompactifAI was applied to produce a smaller, efficient model (16B parameters) while aiming to preserve reasoning and tool-use capabilities. Supervised Fine Tuning was applied for improving cabapilities.
Evaluation & Benchmarks
[Image blocked: Combined benchmark chart]
Quantizations
[Image blocked: Quantization results]
Performance
[Image blocked: Performance results]
- Framework: guidellm
- Inference: vLLM 0.18.0
- GPU: NVIDIA L40s
- Decode:
temperature: 0.0, top_p: 1.0
- Measure Window: Each phase lasts 3 minutes (excluding ramp-up and cool-down periods).
- Workload shape: 8k/16k workload as in the original model's card.
Long Context
Pulsar 16B preserves strong long-context behavior after compression, tracking the Nemotron-3-Nano-30B-A3B baseline closely across retrieval-heavy and full-suite long-context evaluations. Results are reported for LongBench v1, AA-LCR, NIAH, and RULER groupings up to 256k context.
[Image blocked: Long-context benchmark results]
Evaluation Methodology
Benchmark scores were obtained with the following setups. Methodology varies by benchmark family.
Inference:
- Backend: VLLM 0.18.0
- Nemotron models:
temp 1.0, top_p 1.0
- GPT-OSS-20B:
temp: 1.0, top_p: 1.0, reasoning_effort: high
- Qwen3-14B:
temp: 0.6, top_p: 0.95, top_k: 20, min_p: 0.0
- Ministral-3-14B-Instruct-2512:
temp: 0.15
Languages
- Primary language: English
- Other languages: Spanish
Trained mainly on English with added Spanish. No systematic evaluation for languages outside English and Spanish.
Safety & Limitations
Known Limitations
- English-centric training data (inherited from base model).
- Tool calling depends on correct schema and tool design; exact parity with the original model is not guaranteed.
- Compression may affect some behaviors; evaluate for your use case.
Recommendations
- Validate tool outputs before running them
- Human oversight for critical use
- Task-specific eval before production
Model Information
Citation
If you use this model, please cite the base model and Pulsar 16B:
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