GLM-5.3-Flash 320B-A18B — VRAM, Speed & Local Setup

Written by Jakub Rusinowski · Last updated September 11, 2026

Model libraryGLM-5.3-Flash → GLM-5.3-Flash 320B-A18B

320 billion parameters must all be resident — about 194 GB at Q4_K_M, so this is a multi-GPU or large-unified-memory model, not a single-card one. Only 18B activate per token, which is why it decodes at roughly the speed of a 18B dense model once loaded. Natively multimodal across text, image and video with a 1,048,576-token context. MIT licensed. Ollama publishes only a `:cloud` tag; local runners use the community GGUF conversions.

GLM-5.3-Flash 320B-A18B needs about 194 GB of VRAM at Q4_K_M — quantized weights plus framework overhead, before any KV cache. On Apple Silicon that figure comes out of unified memory.

Specifications

Parameters320 Billion (18B active)
Context window1,048,576
ArchitectureHybrid-Attention MoE (multimodal)
ProviderZhipu AI (Z.ai)
LicenceMIT
Specified atQ4_K_M
System RAM256 GB
Record updated2026-09-11

Licence

MITcommercial use permitted. Commercial use permitted. No usage restrictions beyond attribution.

VRAM and Speed by Quantization

Modelled on a reference NVIDIA RTX 4090 (24 GB), with no KV cache (this record has no published architecture). Speed figures are ESTIMATES from the memory-bandwidth roofline described on the methodology page, not benchmarks we ran — rows marked measured come from published or reader-submitted runs. VRAM here includes the KV cache, so it reads higher than the headline figure above, which does not.

QuantWeightsVRAM neededEst. speedFit on 24 GB
Q2_K105.2 GB106.0 GBWon't fit
Q3_K_M136.4 GB137.2 GBWon't fit
Q4_K_M193.2 GB194.0 GBWon't fit
Q5_K_M226.8 GB227.6 GBWon't fit
Q6_K262.4 GB263.2 GBWon't fit
Q8_0340.0 GB340.8 GBWon't fit
F16640.0 GB640.8 GBWon't fit

Want the memory numbers alone, at every quantization level and your own context length? Use the GLM-5.3-Flash 320B-A18B VRAM calculator.

Buy This HardwareApple Mac Studio M3 Ultra — 512 GB VRAM · 60 W board powerDeploy in the Cloud NowRunPod

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Recommended GPU

The cheapest catalogued GPU that runs GLM-5.3-Flash 320B-A18B is the Apple M3 Ultra (512 GB).

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Apple Mac Studio M3 Ultra
512 GB VRAM · 60 W board power
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How to Run GLM-5.3-Flash 320B-A18B

Install Ollama, then run:

ollama run glm-5.3-flash:cloud

Weights on Hugging Face: zai-org/GLM-5.3-Flash.

Published Benchmark Scores

Quality scores as published by the model's authors or an independent evaluator — not throughput, and not measured by us.

BenchmarkScoreProvenance
DeepSWE63.4 / 100 %vendor-claimed · https://www.marktechpost.com/2026/08/26/z-ai-releases-glm-5-3-flash-a-320b-a18b-natively-multimodal-moe-with-a-1m-token-context/

Best for: agentic coding, multimodal, long context, reasoning.

Can I Run GLM-5.3-Flash 320B-A18B on My GPU?

GLM-5.3-Flash 320B-A18B — Frequently Asked Questions

How much VRAM does GLM-5.3-Flash 320B-A18B need?
About 194 GB at Q4_K_M — quantized weights plus framework overhead, before any KV cache. The cache grows with context length and is added on top; the table above folds it in. Apple Silicon counts unified memory toward the same figure.
Does GLM-5.3-Flash 320B-A18B run on an RTX 4090 (24 GB)?
No. GLM-5.3-Flash 320B-A18B needs about 194 GB at Q4_K_M, more than a single RTX 4090's 24 GB. It needs a larger card, several GPUs, or Apple Silicon with enough unified memory — or it runs with part of the weights offloaded to system RAM, which is much slower.
How do I run GLM-5.3-Flash 320B-A18B locally?
Install Ollama and run `ollama run glm-5.3-flash:cloud`. That pulls the weights and starts a local OpenAI-compatible endpoint; after the download nothing leaves the machine.

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