Skip to main content

Model Selection Guide

Selecting the appropriate Qwen model depends on your specific requirements, including task complexity, available compute resources, latency constraints, and budget. This guide helps you make an informed decision.

Quick Decision Tree

Model Comparison Matrix

ModelParametersContextTraining TokensUse CaseMin GPU (Int4)
Qwen-1.8B1.8B32K2.2TEdge/mobile, fast inference2.9GB
Qwen-7B7B32K2.4TGeneral purpose, balanced8.2GB
Qwen-14B14B8K3.0THigh quality, moderate resources13.0GB
Qwen-72B72B32K3.0TMaximum quality, research48.9GB

Selection by Use Case

1. Production Chatbots & Virtual Assistants

Recommended: Qwen-7B-Chat-Int4 or Qwen-14B-Chat-Int4Why:
  • Balanced quality and cost
  • Fast inference speed (~38-50 tokens/s)
  • Fits in single GPU for scalable deployment
  • Strong performance on conversational tasks
Considerations:
  • Use Int4 quantization for cost efficiency
  • Deploy with vLLM for higher throughput
  • Consider batching for concurrent users
Recommended: Qwen-14B-Chat or Qwen-72B-ChatWhy:
  • Superior reasoning and comprehension
  • Better handling of complex queries
  • More accurate information retrieval
  • Professional-grade responses
Considerations:
  • Fine-tune on domain-specific data
  • Use full precision (BF16) for maximum accuracy
  • Qwen-72B requires multi-GPU setup
Recommended: Qwen-1.8B-Chat-Int4Why:
  • Smallest memory footprint (2.9GB)
  • Fastest inference speed (71 tokens/s)
  • Can run on consumer hardware
  • Still maintains reasonable performance
Considerations:
  • Best for simpler conversations
  • May struggle with complex reasoning
  • Ideal for on-device AI applications

2. Code Generation & Programming Assistants

For Production Code Tools

Qwen-14B-Chat or Qwen-7B-Chat
  • HumanEval Pass@1: 32.3% (14B), 29.9% (7B)
  • Good balance of speed and accuracy
  • Handles multiple programming languages
  • Suitable for IDE integration

For Research & Experimentation

Qwen-72B-Chat
  • HumanEval Pass@1: 35.4%
  • Highest code generation quality
  • Better at understanding complex requirements
  • Ideal for code explanation and debugging

3. Fine-tuning & Customization

Qwen-1.8B or Qwen-7BRecommended Method: Q-LoRA
  • Qwen-1.8B: 5.8GB GPU memory
  • Qwen-7B: 11.5GB GPU memory
Ideal For:
  • Single GPU (RTX 3090, 4090, V100)
  • Domain-specific tasks
  • Fast iteration cycles
  • Budget-conscious projects
Limitations:
  • Q-LoRA adapters cannot be merged
  • Slightly slower inference than full fine-tuning

4. Mathematical & Scientific Applications

Performance on GSM8K (Math Word Problems):
ModelAccuracyRecommended For
Qwen-1.8B32.3%Basic calculations, educational apps
Qwen-7B51.7%General math assistance, tutoring
Qwen-14B61.3%Advanced problem solving
Qwen-72B78.9%Research, complex mathematical reasoning
For mathematical applications, Qwen-14B and Qwen-72B show significantly better performance. The 72B model approaches GPT-3.5 level accuracy.

5. Multilingual Applications

All Qwen models support multilingual inference with efficient tokenization:
Any Qwen model performs well
  • C-Eval (Chinese): Qwen-7B scores 63.5 (5-shot)
  • MMLU (English): Qwen-7B scores 58.2 (5-shot)
  • Translation WMT22: Qwen-7B achieves 27.5 BLEU
Recommendation: Start with Qwen-7B for balanced bilingual capabilities

6. Long Context Applications

Context Length Capabilities:
ModelDefault ContextExtended ContextBest For
Qwen-1.8B32KUp to 32KLong documents, summarization
Qwen-7B2048 → 32KUp to 16K+Balanced long-context tasks
Qwen-14B8KUp to 8KModerate context needs
Qwen-72B32KUp to 32KMaximum context understanding
Long context requires enabling dynamic NTK interpolation and LogN attention scaling. See perplexity benchmarks in the base models documentation.

Hardware Recommendations

GPU Requirements by Model

24GB VRAMInference:
  • ✅ Qwen-1.8B (all precisions)
  • ✅ Qwen-7B-Int4/Int8
  • ⚠️ Qwen-7B-BF16 (tight fit)
  • ❌ Qwen-14B+ (requires quantization or splitting)
Fine-tuning (Q-LoRA):
  • ✅ Qwen-1.8B (5.8GB)
  • ✅ Qwen-7B (11.5GB)
  • ⚠️ Qwen-14B (18.7GB, may need gradient checkpointing)
40GB VRAMInference:
  • ✅ Qwen-1.8B, Qwen-7B (all precisions)
  • ✅ Qwen-14B-Int4/Int8
  • ✅ Qwen-14B-BF16 (30GB)
  • ❌ Qwen-72B (requires multi-GPU)
Fine-tuning (LoRA):
  • ✅ Qwen-7B (full precision)
  • ✅ Qwen-14B (with careful configuration)
80GB VRAMInference:
  • ✅ All models up to 14B (all precisions)
  • ✅ Qwen-72B-Int4 (48.9GB)
  • ⚠️ Qwen-72B-Int8 (requires 2×GPU)
Fine-tuning:
  • ✅ Qwen-7B (full parameter)
  • ✅ Qwen-14B (LoRA/Q-LoRA)
  • ✅ Qwen-72B (Q-LoRA at 61.4GB)
2×A100 80GB or betterInference:
  • ✅ Qwen-72B-BF16 (144GB)
  • ✅ Qwen-72B-Int8 (81GB)
  • ✅ With vLLM: 17.6 tokens/s (BF16)
Fine-tuning:
  • ✅ Qwen-14B (full parameter)
  • ✅ Qwen-72B (LoRA with DeepSpeed ZeRO 3)

Cost-Performance Analysis

Inference Cost Estimation

Assuming A100 GPU pricing and average utilization:
ModelPrecisionGPU Cost/hrThroughputCost per 1M tokens
Qwen-7B-Int4Int4~$350 tok/s~$17
Qwen-7B-BF16BF16~$341 tok/s~$20
Qwen-14B-Int4Int4~$339 tok/s~$21
Qwen-72B-Int4Int4~$311 tok/s~$76
Qwen-72B-BF16+vLLMBF16~$6 (2×GPU)18 tok/s~$93
Actual costs vary by cloud provider, region, and negotiated rates. Int4 quantization provides the best cost-performance ratio.

Decision Matrix

By Primary Constraint

Priority: Best possible outputs, regardless of cost
  1. Qwen-72B-Chat (BF16) - Maximum quality
  2. Qwen-14B-Chat (BF16) - Very high quality, more accessible
  3. Qwen-7B-Chat (BF16) - Good quality baseline
Use Cases: Research, premium products, critical applications

Common Scenarios

Scenario 1: Startup Building a Chatbot MVP

Requirements: Fast iteration, low cost, decent quality Recommendation: Qwen-7B-Chat-Int4 Rationale:
  • Fits in single GPU (8.2GB)
  • Good performance on benchmarks (MMLU 55.1)
  • Fast inference (50 tokens/s)
  • Can fine-tune with Q-LoRA on single GPU
  • Easy to upgrade to larger model later

Scenario 2: Enterprise Knowledge Management System

Requirements: High accuracy, complex reasoning, domain-specific Recommendation: Qwen-14B-Chat fine-tuned on internal data Rationale:
  • Strong comprehension (MMLU 64.6)
  • Sufficient for enterprise deployment
  • Fine-tuning improves domain adaptation
  • Reasonable infrastructure cost

Scenario 3: Research in Long-Form Text Generation

Requirements: State-of-the-art quality, long context Recommendation: Qwen-72B-Chat with extended context Rationale:
  • Best performance across all benchmarks
  • 32K context length support
  • Comparable to GPT-3.5
  • Ideal for research and experimentation

Scenario 4: Mobile App with On-Device AI

Requirements: Extremely low latency, offline capability Recommendation: Qwen-1.8B-Chat-Int4 Rationale:
  • Smallest model (2.9GB)
  • Fastest inference (71 tokens/s)
  • Can run on mobile GPUs
  • Still provides reasonable chat quality

Migration Path

Many projects benefit from starting small and scaling up: Benefits:
  • Lower initial investment
  • Faster iteration during development
  • Clear upgrade path as needs grow
  • Code remains compatible across models

Final Recommendations

Most Versatile

Qwen-7B-Chat-Int4Best all-around choice for production applications. Balances quality, speed, and cost effectively.

Best Value

Qwen-1.8B-Chat-Int4Lowest cost option that still delivers reasonable performance. Ideal for high-scale deployment.

Highest Quality

Qwen-72B-ChatState-of-the-art results across all benchmarks. Choose when quality is paramount.

Fine-tuning

Qwen-7B (base)Best starting point for custom fine-tuning with Q-LoRA on consumer hardware.

Next Steps

Base Models

Detailed specifications

Chat Models

Chat model capabilities

Quickstart

Start using Qwen

Quantization

Reduce memory usage

Fine-tuning

Customize models

Deployment

Deploy to production

Build docs developers (and LLMs) love