Qwen 3.5 Medium Series VRAM Requirements: 27B, 35B, 122B GPU Deployment Guide

Qwen3.5 Vram Requirements

Qwen 3.5 Medium Series (27B, 35B-A3B, 122B-A10B) offers enterprise-grade language models with varying VRAM needs:

  • 27B: 17-54 GB (Q4_K_M to BF16)
  • 35B-A3B: 22-69 GB (Q4_K_M to BF16)
  • 122B-A10B: 77-244 GB (Q4_K_M to BF16)

Deploy on Novita AI with flexible GPU options (H100, RTX 5090, RTX 4090) or serverless API for zero infrastructure management.

What is Qwen 3.5 Medium Series

Qwen 3.5 Medium Series comprises three high-performance language models designed for production-grade applications:

  • Qwen3.5-27B: 27B parameters, balanced performance for general tasks
  • Qwen3.5-35B-A3B: 35B total parameters with 3B active per token (MoE architecture)
  • Qwen3.5-122B-A10B: 122B total parameters with 10B active per token (MoE architecture)

These models excel in reasoning, coding, multilingual understanding, and long-context processing.

Understanding VRAM requirements is critical for cost-effective deployment—whether you’re running on dedicated GPUs or leveraging serverless infrastructure.

VRAM Requirements by Model and Precision

VRAM needs vary significantly based on quantization precision. Below are memory requirements based on Hugging Face hardware compatibility data.

⚠️ Note: These figures represent model weight sizes. Actual VRAM usage during inference will be 10-30% higher depending on batch size, context length, and KV cache overhead. We recommend choosing GPUs with at least 10-20% headroom.

Qwen3.5-27B-GGUF

QuantizationVRAM (GB)Recommended Hardware
BF1654GPU: A100 × 1 (80GB) / H100 × 1 (80GB)
Q8_029CPU: Intel Sapphire Rapids 16× vCPUs · 32 GB RAM
GPU: A100 40GB / RTX 4090 24GB (faster inference)
Q4_K_M17CPU: Intel Sapphire Rapids 16× vCPUs · 32 GB RAM
GPU: RTX 4090 24GB / L40S 48GB (faster inference)

💡 CPU vs GPU: At Q8_0 and Q4_K_M precision, the model fits within modern CPU RAM limits (32-64 GB). However, GPU inference is 10-50× faster depending on batch size. For production workloads requiring low latency or high throughput, GPU deployment is strongly recommended.

Qwen3.5-35B-A3B-GGUF

QuantizationVRAM (GB)Recommended Hardware
BF1669GPU: A100 × 1 (80GB) / H100 × 1 (80GB)
Q8_037GPU: L40S × 1 (48GB) / A100 40GB
Q4_K_M22CPU: Intel Sapphire Rapids 16× vCPUs · 32 GB RAM
GPU: RTX 4090 24GB / L40S 48GB (faster inference)

Qwen3.5-122B-A10B-GGUF

QuantizationVRAM (GB)Recommended Hardware
BF16244GPU: A100 × 4 (320GB) / H100 × 4 (320GB)
Q8_0130GPU: A100 × 2 (160GB) / H100 × 2 (160GB)
Q4_K_M77GPU: A100 × 1 (80GB) / H100 × 1 (80GB)

💡 Note: The 122B model requires high-end GPUs even with aggressive quantization due to its size. Multi-GPU setups are essential for BF16 and Q8_0 precision.

Deploying on Novita AI

Novita AI provides flexible deployment options for Qwen 3.5 Medium Series, balancing performance, cost, and ease of use.

GPU Deployment (Recommended for VRAM-Focused Users)

Novita AI offers high-performance GPUs optimized for deploying Qwen 3.5 models with flexible billing options:

Recommended GPU Configurations

ModelQuantizationVRAM NeededRecommended GPUUse Case
27BBF1654 GBH100 80GB / RTX 5090 32GB × 2Production, max quality
27BQ8_029 GBRTX 5090 32GB / RTX 4090 24GB × 2Balanced performance
27BQ4_K_M17 GBRTX 4090 24GBCost-effective inference
35B-A3BBF1669 GBH100 80GBProduction, max quality
35B-A3BQ8_037 GBRTX 5090 32GB × 2 / H100 80GBBalanced performance
35B-A3BQ4_K_M22 GBRTX 4090 24GBCost-effective inference
122B-A10BBF16244 GBH100 80GB × 4Enterprise, max quality
122B-A10BQ8_0130 GBH100 80GB × 2Balanced performance
122B-A10BQ4_K_M77 GBH100 80GBCost-effective inference

Why Novita AI GPU Deployment?

Novita AI provides GPU options across multiple performance tiers to match your workload and budget:

  • Enterprise-grade GPUs: High-VRAM configurations for BF16 and Q8_0 precision
  • High-performance consumer GPUs: Balanced price/performance for medium-sized models
  • Cost-effective options: Affordable configurations for quantized models (Q4_K_M)
  • Multi-GPU setups: Seamlessly scale from 1× to 8× GPU configurations
  • Flexible billing: On-demand, spot instances, and serverless GPUs (pay-per-second)
  • Instant deployment: Pre-configured templates for rapid setup

Serverless API (Zero Infrastructure Alternative)

For users who prefer zero infrastructure management, Novita AI offers Serverless API endpoints with OpenAI-compatible interfaces.

Supported Models

ModelModel ID
Qwen3.5-27Bqwen/qwen3.5-27b
Qwen3.5-35B-A3Bqwen/qwen3.5-35b-a3b
Qwen3.5-122B-A10Bqwen/qwen3.5-122b-a10b

How to Get API Key

  1. Sign up at Novita AI
  2. Navigate to API Keys section in your dashboard
  3. Click Create New Key and copy your API key
  4. Add credits to your account to start using the API
how to get api key to use qwen 3.5

Quick Example:

from openai import OpenAI

client = OpenAI(
    api_key="<Your API Key>",
    base_url="https://api.novita.ai/openai"
)

response = client.chat.completions.create(
    model="qwen/qwen3.5-35b-a3b",
    messages=[
        {"role": "system", "content": "You are a helpful assistant."},
        {"role": "user", "content": "Hello, how are you?"}
    ],
    max_tokens=65536,
    temperature=0.7
)

print(response.choices[0].message.content)

Choosing the Right Precision

BF16 (Full Precision)

  • Use case: Production environments requiring maximum quality
  • Trade-off: Highest VRAM requirements
  • Best for: Enterprise applications, research benchmarks

Q8_0 (8-bit Quantization)

  • Use case: Balanced performance and efficiency
  • Trade-off: ~1-2% quality loss, 50% VRAM reduction
  • Best for: High-throughput inference, cost-sensitive production

Q4_K_M (4-bit Quantization)

  • Use case: Cost-effective deployment on consumer GPUs
  • Trade-off: ~3-5% quality loss, 70-75% VRAM reduction
  • Best for: Development, testing, budget-constrained deployments

Conclusion

Qwen 3.5 Medium Series offers powerful language models for diverse enterprise needs, with VRAM requirements ranging from 17 GB (27B Q4_K_M) to 244 GB (122B BF16).

Key takeaways:

  • Choose quantization based on quality vs. cost trade-offs
  • GPU inference is 10-50× faster than CPU for production workloads
  • Novita AI provides flexible deployment: GPU rental (on-demand/spot) or serverless API

Next steps:

  1. Determine your model size and precision needs
  2. Explore Novita AI’s GPU pricing or API endpoints
  3. Deploy in minutes with pre-configured templates

Novita AI is an AI cloud platform that offers developers an easy way to deploy AI models using our simple API, while also providing affordable and reliable GPU cloud for building and scaling.

Frequently Asked Questions

What is VRAM?

VRAM (Video Random Access Memory) is dedicated memory on your GPU used to store model weights, activations, and intermediate calculations during inference. For LLMs like Qwen 3.5, VRAM requirements scale with model size and precision—larger models and higher precision (e.g., BF16) need more VRAM than quantized versions (e.g., Q4_K_M). Insufficient VRAM will cause out-of-memory errors or force you to use CPU inference, which is significantly slower.

Can I run Qwen 3.5 Medium models on CPU?

Yes, smaller quantized models (Q8_0 and Q4_K_M) can run on CPUs with 32-64 GB of RAM. However, CPU inference is 10-50× slower than GPU, making it impractical for production workloads or real-time applications. For best performance, GPU deployment is strongly recommended even for quantized models.

What’s the difference between BF16, Q8_0, and Q4_K_M?

BF16 (16-bit) is full precision with maximum quality but highest VRAM usage. Q8_0 (8-bit) reduces VRAM by ~50% with minimal quality loss (~1-2%). Q4_K_M (4-bit) cuts VRAM by 70-75% but may introduce 3-5% quality degradation—ideal for cost-sensitive deployments where slight accuracy trade-offs are acceptable.


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