willitrun·ai

Can Qwen3.5 35B A3B run on RX 7900 XT 20GB?

YES — With Q2_K

C49Usable
Estimated from fit model

Qwen3.5 35B A3B needs ~20.7 GB VRAM. RX 7900 XT 20GB has 20.0 GB. With Q2_K quantization, expect ~21 tok/s.

Runtime: llama.cppCapacity: OffloadBandwidth: HighStack: StandardBottleneck: Balanced
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Operating mode

Choose the run profile you care about

Interactive favors responsiveness, while light API and scale-out lean harder on serving readiness. The fit stays the same, but the recommendation lens changes.

Current mode

Balanced

Balanced for general local use. Keeps the ranking neutral across personal and serving workflows.

Qwen3.5 35B A3B at Q4_K_M needs 28.4 GB — too much for RX 7900 XT 20GB (20.0 GB). Runs at Q2_K (20.7 GB) with low quality.
Capabilities:

Select quantization to explore

Q4_K_M (Medium quality) 28.4 GB, exceeds 20.0 GB available
28.4 GB required20.0 GB available
142% VRAM needed

8.4 GB over capacity — needs offload or smaller quantization

Fit status

Too heavy

Decode

8.1 tok/s

TTFT

23934 ms

Safe context

4K

Memory

28.4 GB / 20.0 GB

Offload

30%

Memory breakdown

Weights21.3 GB
KV Cache4.1 GB
Runtime0.9 GB
Headroom2.0 GB

See how fast it feels

With memory offload — actual speed may be lower
See how fast it feelsQwen3.5 35B A3B on RX 7900 XT 20GB
1st promptCold start — includes initialization
>What is local AI inference?
Local AI inference means running an AI language model directly on your own hardware — your laptop, desktop, or server — instead of sending requests to a remote cloud API. When you run inference locally the model weights are loaded into your GPU or unified memory. Each token you generate requires reading those weights from memory, so memory bandwidth is the main bottleneck for decode speed. Key benefits of running locally: - Full privacy: your prompts never leave your machine - No per-token cost or rate limits - Works offline once the model is downloaded - Latency depends only on your hardware
2nd promptWarm — model ready, no init overhead
>How much VRAM do I need?
It depends on the model size and quantization level. A rough rule of thumb: Model size Q4 (4-bit) Q8 (8-bit) FP16 7B params ~4.3 GB ~7.5 GB ~14 GB 13B params ~7.9 GB ~13.9 GB ~26 GB 70B params ~42.7 GB ~74.9 GB ~140 GB Most people use 4-bit quantization (Q4_K_M) which gives 90-95% of full quality at a fraction of the memory. A 24 GB GPU can comfortably run most 7B-13B models.
Estimated: 8.1 tok/s decode · 23.9s TTFT (warm) · 20 tok/s prefill

What limits this setup

This setup is broadly balanced for this model.

Very little memory headroom

You can run the model, but there is not much room left for longer context, bigger batches, extra apps, or future model updates.

Best improvement path

Buy headroom, not only minimum fit

A slightly larger memory tier gives you safer context growth and makes the recommendation more future-proof.

Performance by workload

WorkloadGradeFitDecodeTTFTContext
ChatFToo heavy9.5 tok/s11146 ms4K
CodingFToo heavy8.1 tok/s23934 ms4K
Agentic CodingFToo heavy6.1 tok/s46265 ms4K
ReasoningFToo heavy8.1 tok/s28285 ms4K
RAGFToo heavy6.1 tok/s57832 ms4K

Inference speed

Qwen3.5 35B A3B inference speed — tokens per second by GPU & Mac

Estimated decode speed (tokens/sec) for Qwen3.5 35B A3B at Q4_K_M across popular GPUs and Apple Silicon, using the fastest local runtime per device. Fastest is RTX 5090 32GB at ~56 tok/s. Speed is memory-bandwidth bound, so cards that fit the whole model in VRAM run far faster than ones that offload to system RAM.

GPU / MacMemoryQuantSpeed (tok/s)Fits?
NVIDIARTX 5090 32GB
32 GBQ4_K_M56.2Tight
MacBook Pro M4 Max 128GB
128 GBQ4_K_M28.1Fits
MacBook Pro M4 Max 64GB
64 GBQ4_K_M28.1Fits
Mac Studio M3 Ultra 256GB
256 GBQ4_K_M26.1Fits
Mac Studio M2 Ultra 128GB
128 GBQ4_K_M21.7Fits
Mac Studio M1 Ultra 128GB
128 GBQ4_K_M20.6Fits
MacBook Pro M4 Pro 48GB
48 GBQ4_K_M17.7Tight
RX 7900 XTX 24GB
24 GBQ4_K_M16.6Heavy offload
MacBook Pro M3 Max 64GB
64 GBQ4_K_M11.2Fits
NVIDIARTX 4090 24GB
24 GBQ4_K_M10.6Heavy offload
MacBook Pro M1 Max 64GB
64 GBQ4_K_M10.3Fits
NVIDIARTX 3090 24GB
24 GBQ4_K_M9.7Heavy offload
NVIDIARTX 4080 Super 16GB
16 GBQ4_K_M6.5Too big
NVIDIARTX 4070 12GB
12 GBQ4_K_M2.7Too big
NVIDIARTX 3060 12GB
12 GBQ4_K_M2.0Too big
NVIDIARTX 4060 8GB
8 GBQ4_K_M2.0Too big

Estimates for single-stream decoding at Q4_K_M; real tokens/sec varies with prompt length, context, batch size, and runtime build. Prompt processing (prefill) is faster than the decode figures shown here.

Quantization options

How Qwen3.5 35B A3B (35B params) fits at each quantization level on RX 7900 XT 20GB (20.0 GB usable).

QuantBitsVRAMQualityFit
Q2_KBest for your GPU
2
13.7 GB
LowC50
Q3_K_S
3
17.2 GB
LowF0
NVFP4
4
19.6 GB
MediumF0
Q4_K_M
4
21.3 GB
MediumF0
Q5_K_M
5
25.2 GB
HighF0
Q6_K
6
28.7 GB
HighF0
Q8_0
8
37.5 GB
Very HighF0
F16
16
71.8 GB
MaximumF0

Get started

Copy-paste commands to run Qwen3.5 35B A3B on your machine.

Run

docker run --rm -it ghcr.io/ggerganov/llama.cpp:full \ --hf-repo "lmstudio-community/Qwen3.5-35B-A3B-GGUF" \ --hf-file "Qwen3.5-35B-A3B-GGUF-Q4_K_M.gguf" \ -c 4096 -ngl 99

升级选项

能流畅运行 Qwen3.5 35B A3B 的硬件

Frequently asked questions

Can RX 7900 XT 20GB run Qwen3.5 35B A3B?

Yes, RX 7900 XT 20GB can run Qwen3.5 35B A3B at Q2_K quantization (Runs with offload (needs ~0.4 GB host RAM)). The recommended Q4_K_M requires 28.4 GB which exceeds available memory, but at Q2_K it needs only 20.7 GB. Expected decode speed: 21.0 tok/s.

How much VRAM does Qwen3.5 35B A3B need?

Qwen3.5 35B A3B (35B parameters) requires approximately 28.4 GB at Q4_K_M quantization. On RX 7900 XT 20GB, it fits at Q2_K using 20.7 GB.

What is the best quantization for Qwen3.5 35B A3B?

The recommended quantization is Q4_K_M, but on RX 7900 XT 20GB the best fitting quantization is Q2_K, which uses 20.7 GB.

What speed will Qwen3.5 35B A3B run at on RX 7900 XT 20GB?

On RX 7900 XT 20GB, Qwen3.5 35B A3B achieves approximately 21.0 tokens per second decode speed with a time-to-first-token of 9239ms using Q2_K quantization.

Can RX 7900 XT 20GB run Qwen3.5 35B A3B for coding?

For coding workloads, Qwen3.5 35B A3B on RX 7900 XT 20GB receives a F grade with 8.1 tok/s and 4K context.

What context window can Qwen3.5 35B A3B use on RX 7900 XT 20GB?

On RX 7900 XT 20GB, Qwen3.5 35B A3B can safely use up to 13K tokens of context at Q2_K quantization. The model's official context limit is —, but available memory constrains the safe maximum.

What should I upgrade first if Qwen3.5 35B A3B feels slow on RX 7900 XT 20GB?

Buy headroom, not only minimum fit. A slightly larger memory tier gives you safer context growth and makes the recommendation more future-proof.

See all results for RX 7900 XT 20GBSee all hardware for Qwen3.5 35B A3B
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<iframe src="https://willitrunai.com/embed/hf-lmstudio-community--qwen3-5-35b-a3b-gguf-on-rx-7900-xt-20gb" width="400" height="180" frameborder="0" style="border:none;border-radius:12px;overflow:hidden;" title="Will It Run AI — fit result"></iframe>

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