Qwen3-235B-A22B (MoE) — VRAM Requirements, Quantization Matrix & GPU Guide

Qwen3-235B-A22B (MoE) (Qwen, Apache-2.0) is a Mixture-of-Experts (MoE) architecture with 235B resident parameters (22B active per token), 94 layers, and Grouped-Query Attention (GQA) supporting up to 40,960 context tokens.

Interactive Qwen3-235B-A22B (MoE) Memory & Context Simulator

32,768 tokens

Memory Breakdown & Bandwidth Ceiling

Tight Fit (>90% Usable)
Model Weights: 93.9% KV: 4.2% Overhead: 1.9%
Total Required Memory
141.35 GB
Per-Device Allocation: 141.35 GB
Model Weights
132.68 GB
KV Cache (FP16): 5.88 GB
Est. Single-Stream Decode
24.0 tok/s
Runtime & TP Overhead: 2.79 GB
Max Context Before OOM
177,059
tokens

Architecture KV compression saves 93.8% vs naive MHA FP16 (94.00 GB).

macOS caps GPU wired memory around 144.0 GB (75%) by default; raising iogpu.wired_limit_mb unlocks up to 169.0 GB (88%).

sudo sysctl iogpu.wired_limit_mb=173015

Precision & Quantization VRAM Matrix (8K / 32K / 128K Context)

Total GPU memory required across weight precisions and context lengths (batch = 1, FP16 KV cache)
Precision / Format Effective bpw Weights Only Total @ 8K ctx Total @ 32K ctx Total @ 128K ctx Recommended Tier (@ 32K)
FP16 / BF16 16.00 bpw 437.72 GB 446.56 GB 450.96 GB 468.59 GB 8× NVIDIA H100 80GB
FP8 8.50 bpw 232.54 GB 238.30 GB 242.70 GB 260.33 GB Mac Studio 512GB
Q8_0 8.50 bpw 232.54 GB 238.30 GB 242.70 GB 260.33 GB Mac Studio 512GB
Q6_K 6.56 bpw 179.47 GB 184.43 GB 188.83 GB 206.46 GB Mac Studio 512GB
Q5_K_M 5.69 bpw 155.66 GB 160.27 GB 164.67 GB 182.30 GB Mac Studio 512GB
Q4_K_M 4.85 bpw 132.68 GB 136.94 GB 141.35 GB 158.97 GB Mac Studio 192GB
AWQ INT4 4.50 bpw 123.11 GB 127.22 GB 131.63 GB 149.26 GB NVIDIA H200 141GB
IQ4_XS 4.25 bpw 116.27 GB 120.28 GB 124.69 GB 142.31 GB NVIDIA H200 141GB

Hardware Compatibility & Decode Speed (Qwen3-235B-A22B (MoE) @ Q4_K_M, 32K Context)

Fit status, memory utilization, and estimated decode throughput across flagship GPUs and Apple Silicon
Hardware Tier Memory & Bandwidth Required (32K) Fit Verdict Est. Decode Speed
RTX 3090 24GB 24 GB · 936 GB/s 143.68 GB (599%) Out of Memory (OOM) —
RTX 4090 24GB 24 GB · 1008 GB/s 143.68 GB (599%) Out of Memory (OOM) —
RTX 5090 32GB 32 GB · 1792 GB/s 143.68 GB (449%) Out of Memory (OOM) —
Apple M-Max 64GB 64 GB · 546 GB/s 141.35 GB (221%) Out of Memory (OOM) —
Mac Studio 128GB 128 GB · 546 GB/s 141.35 GB (110%) Out of Memory (OOM) —
Mac Studio 192GB 192 GB · 800 GB/s 141.35 GB (74%) Tight Fit (>90% Usable) 24.0 tok/s
NVIDIA A100 80GB 80 GB · 2039 GB/s 143.68 GB (180%) Out of Memory (OOM) —
NVIDIA H100 80GB 80 GB · 3350 GB/s 143.68 GB (180%) Out of Memory (OOM) —

Verified Transformer Architecture Parameters

Checkpoint ID
Qwen/Qwen3-235B-A22B
Ollama Tag
qwen3:235b
License / Release
Apache-2.0 · 2025-Q2
Topology & Attention
Mixture-of-Experts (MoE)
Attention Mechanism
Grouped-Query Attention (GQA)
Total Params (B)
235B
Active Params / Token (B)
22B
Hidden Layers / Hidden Size
94 / 4096
Query Heads / KV Heads
64Q / 4KV (d=128)
MoE Routed Experts
8 active / 128 total
Vocab / Max Position
151,936 / 40,960

Quantized formats store per-block scale factors and zero-points alongside packed integer weights. A 4-bit GGUF Q4_K_M checkpoint averages 4.85 effective bits per parameter (not 4.00), while Q8_0 averages 8.50 bpw. For Mixture-of-Experts models, all routed and shared experts remain resident in memory to prevent token-by-token host paging.

Standard Grouped-Query Attention allocates 2 × L × H_kv × d_head × S × B × bytes_kv across layers. DeepSeek Multi-head Latent Attention (MLA) compresses keys and values into L × (d_kv_lora + d_qk_rope) × S × B × bytes_kv, slashing long-context memory by over 90%. Hybrid sliding-window models cap local-attention layers at min(S, window_size) while scaling global layers linearly with S.

Quick-Start vLLM & Ollama Commands for Qwen3-235B-A22B (MoE)

vLLM CLI (Mac Studio 192GB)
vllm serve Qwen/Qwen3-235B-A22B \
  --tensor-parallel-size 1 \
  --max-model-len 32768 \
  --max-num-seqs 8 \
  --gpu-memory-utilization 0.88 \
  --kv-cache-dtype fp8 \
  --enable-prefix-caching \
  --port 8000
Ollama Modelfile
# Optional macOS unified-memory ceiling override before launching:
# sudo sysctl iogpu.wired_limit_mb=173015

# Save as Modelfile, then run: ollama create qwen3-235b-a22b-custom -f Modelfile
FROM qwen3:235b
PARAMETER num_ctx 32768
PARAMETER num_batch 512
PARAMETER flash_attn true

# Environment variables for ollama serve:
# OLLAMA_NUM_PARALLEL=8 OLLAMA_FLASH_ATTENTION=1 OLLAMA_KV_CACHE_TYPE=q8_0 ollama serve

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