elastix-ai/HyperPrune-Llama-3.1-8B-4to8

TEXT GENERATIONPricing:Input $0.37 / Cached $0.074 / Output $0.38Concurrent Unit Cost:1Model Size:8BQuant:FP8Context Size:8kTool Calling:SupportedPublished:Sep 6, 2026License:otherArchitecture:Transformer Featherless Exclusive Cold

The elastix-ai/HyperPrune-Llama-3.1-8B-4to8 model is a Llama-3.1-8B variant that has been pruned to 4:8 semi-structured sparsity using the HyperPrune method. This 8 billion parameter model achieves a 50% sparsity across all decoder layers, making it significantly more efficient while maintaining strong performance. It is optimized for deployment scenarios where reduced model size and faster inference are critical, offering a WikiText-2 word perplexity of 16.39.

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HyperPrune-Llama-3.1-8B-4to8 Overview

This model is a Llama-3.1-8B variant, developed by elastix-ai, that has undergone 4:8 semi-structured sparsity pruning using the HyperPrune method. It achieves a 50% sparsity across all 32 decoder layers, meaning only 4 out of every 8 weights are retained, leading to a more compact and efficient model.

Key Characteristics & Performance

  • Sparsity: Strict 4:8 semi-structured sparsity applied to all decoder layers, resulting in 50% overall decoder sparsity.
  • Perplexity: Achieves a WikiText-2 word perplexity of 16.39 (using BLADE's lm-eval-harness protocol), a notable improvement over 2:4 sparsity models (22.27 word-perplexity).
  • Efficiency: The pruning process significantly reduces the model's computational footprint, with training wall-clock time of just 20.4 minutes and peak GPU usage of 10.88 GB during cascade fine-tuning.
  • Reproducibility: This checkpoint is a reproduction run by Elastix as part of the BLADE sparsity-method comparison, using DKYoon/SlimPajama-6B as the calibration corpus.
  • Compatibility: Loads directly with stock transformers library, making it easy to integrate into existing workflows.

What Makes It Different

Unlike standard HyperPrune configurations, this model prunes every decoder layer to achieve a true 4:8 sparsity, rather than leaving some layers dense. It also utilizes an N:M generalization of HyperPrune, allowing for flexible sparsity patterns beyond the default 2:4. This specific implementation demonstrates the effectiveness of 4:8 sparsity in significantly improving perplexity compared to 2:4 patterns for Llama-3.1-8B.

Ideal Use Cases

This model is particularly well-suited for applications requiring:

  • Resource-constrained environments: Where memory and computational resources are limited.
  • Faster inference: The reduced parameter count can lead to quicker response times.
  • Efficient deployment: For edge devices or large-scale deployments where model size is a critical factor.