HighVRAM Hardware Watch

Qwen3-30B-A3B VRAM requirements: 16GB, 24GB, 32GB or 48GB?

Short answer: Qwen’s official Qwen3-30B-A3B GGUF files range from 18.6GB for Q4_K_M to 32.5GB for Q8_0. That makes 24GB a practical starting tier for the official Q4 and selected Q5 files, 32GB a stronger fit for Q6_K but still too small for the displayed Q8_0 file, and 48GB the first common tier with substantial working room for every listed quantization. Add KV cache, runtime buffers, context, concurrency and other GPU users before calling any tier a fit.

A3B does not mean a 3B memory requirement. Qwen describes the model as 30.5B total parameters with 3.3B activated per token. All experts still belong to the stored model; use the exact artifact size—not the active count—as the weight-memory floor.

Official Qwen3-30B-A3B GGUF sizes

Official artifactDisplayed sizeMemory-tier implication before overhead
Q4_K_M18.6GBExceeds 16GB; targets 24GB with workload-specific headroom checks
Q5_021.1GBFits below the 24GB label but leaves limited nominal margin
Q5_K_M21.7GBTight 24GB target after cache and runtime allocations
Q6_K25.1GBExceeds 24GB; targets 32GB or a deliberate split/offload plan
Q8_032.5GBExceeds 32GB before cache and buffers; targets 48GB+
Official Qwen repository display values. File size is not peak resident memory, and quantization labels alone do not establish quality or speed.

Why 3.3B active parameters do not make it a 3B model

Qwen publishes 30.5B total parameters, 29.9B non-embedding parameters, 128 experts and eight experts activated for each token. Routing a token through only part of the expert network can reduce per-token compute relative to activating every expert, but the runtime still needs access to all stored expert weights unless it uses an explicit placement or offload strategy.

For memory planning, compare Qwen3-30B-A3B with other roughly 30B stored-weight artifacts—not with a dense 3B model. Use the MoE memory guide for the general total-versus-active rule.

Illustrative KV-cache payload at 8K and 32K

Qwen’s official configuration publishes 48 layers, four KV heads and a 128-element head dimension. For one sequence with FP16 key and value entries, the illustrative payload is:

2 × layers × KV heads × head dimension × bytes × token slots

Allocated token slotsIllustrative FP16 K+V payloadWhat it excludes
8,1920.1875GiBWeights, metadata, runtime buffers, allocator overhead and other GPU users
32,7680.75GiBThe same exclusions; concurrency can multiply sequence-specific state
40,9600.9375GiBThe same exclusions; actual runtime allocation can differ
Architecture arithmetic, not a measured peak-memory claim. Cache precision, paging, alignment, batching and runtime implementation can change resident memory.

Can Qwen3-30B-A3B run on 16GB?

Not with any of Qwen’s five official GGUF artifacts listed above: the smallest official file is 18.6GB. Community low-bit conversions may be smaller, but they are different artifacts with their own quality and compatibility tradeoffs. CPU offload or split placement can make a larger file load, but that is not the same as keeping the complete workload inside 16GB of VRAM.

Can it run on 24GB?

Q4_K_M at 18.6GB is the clearest official 24GB target. Q5_0 at 21.1GB and Q5_K_M at 21.7GB leave much less nominal room, so context, cache precision, buffers, desktop use and concurrent requests matter more. Q6_K at 25.1GB does not fit below the 24GB label before any overhead.

What does 32GB change?

Thirty-two gigabytes gives Q4/Q5 files more working room and can accommodate the displayed 25.1GB Q6_K file with a larger nominal margin. It still does not hold the official 32.5GB Q8_0 file before cache and runtime allocations. Treat 32GB as a broad Q4-through-Q6 tier for this exact repository, not a universal all-quantization guarantee.

When does 48GB make sense?

Forty-eight gigabytes can hold every listed official GGUF artifact with materially more capacity for cache, runtime state, longer context or concurrency. That extra capacity does not promise higher tokens per second. GPU architecture, bandwidth, compute, kernels, cooling and runtime optimization still determine measured performance.

One sourced performance profile—not a universal benchmark

The HighVRAM benchmark database preserves an MLX-LM maintainer report for Qwen3-30B-A3B-Instruct-2507 q4 on an Apple M4 Max system with 64GB reported host memory. For the source’s 2,048-prompt/128-generated-token command, it reports 1,753.90 prompt-processing tokens/s and 113.33 generation tokens/s.

This is one source configuration group, not two independent runs or a GPU ranking. The source does not report batch size, concurrency, configured context, trial count, aggregation, cache state, timing boundaries, TTFT or measured power. Its generic 18.20GB memory column has no defined measurement boundary, so HighVRAM does not publish it as peak model memory. The dependency-version date is not treated as an execution timestamp, and the source’s q4 label is not relabeled as GGUF Q4_K_M.

A reproducible validation checklist

  1. Record the exact Qwen repository revision and GGUF artifact.
  2. Confirm the runtime supports Qwen3-MoE and the selected quantization.
  3. Set context, cache precision, concurrency and maximum output.
  4. Add display use, buffers and other GPU allocations.
  5. Measure peak device memory during the longest representative request.
  6. Evaluate output quality for the selected quantization.
  7. Record throughput separately; capacity is not a speed result.

Vision-language sibling: the Qwen3-VL 30B-A3B VRAM guide adds official projector files, DeepStack vision and complete multimodal workload checks.

Sources and limits

Reviewed October 25, 2026. Repository sizes and architecture fields are from Qwen’s official pages. Cache calculations are illustrative payload arithmetic. HighVRAM has not independently benchmarked every configuration. Capacity does not establish speed, output quality or value.

Ready to choose hardware? Compare 24GB, 32GB and 48GB GPU paths for Qwen3-30B-A3B and dense 32B models.

Need dense Qwen3-8B instead?

The Qwen3-8B guide covers the official dense model and GGUF files rather than the 30B-total/3B-active MoE model.

Dense Qwen3-14B alternative

The Qwen3-14B guide covers the official dense model, distinct from the 30B-total/3B-active MoE architecture.

Dense Qwen3-32B comparison

The Qwen3-32B guide covers the adjacent dense architecture, official files and its different cache geometry.

Compare dense Qwen3 sizes

The dense Qwen3 family guide compares official 4B, 8B, 14B and 32B files before you choose this 30B-total/3B-active MoE alternative.