Z.ai · Released July 2025
GLM-4.5-Air
What it takes to run GLM-4.5-Air locally: memory by quantization, the GPUs that handle it, and how fast it runs.
Updated
- Parameters
- 106B (12B active)
- Architecture
- Mixture of experts
- Context
- 128K tokens
- License
- MIT license
- Memory at Q4_K_M
- ~68GB
What do you need to run GLM-4.5-Air?
GLM-4.5-Air needs about 68GB of VRAM at Q4_K_M with 8K context (64GB for the weights plus KV cache and overhead). The smallest GPU that can hold it is a 72GB card like the RTX PRO 5000 72GB, with little memory to spare. For a good balance of price and speed we recommend the RTX PRO 6000 (~80 tokens/sec). Because it is a mixture-of-experts model with 12B active parameters, it generates text much faster than a dense model of the same size, and it tolerates partial CPU offload better.
What to buy
GPUs for GLM-4.5-Air
Speeds are estimates at the quantization shown with 8K context. We may earn a commission when you buy through these links. Learn more.
Memory
GLM-4.5-Air VRAM requirements by quantization
Lower-bit quantizations shrink the model at some cost to quality. Q4_K_M is the usual sweet spot. Totals include the KV cache for the context length shown plus runtime overhead.
| Quantization | Quality | Weights | Total @ 8K ctx | Total @ 32K ctx |
|---|---|---|---|---|
| Q2_K | Rough | 40 GB | 43 GB | 48 GB |
| Q3_K_M | Usable | 52 GB | 55 GB | 60 GB |
| Q4_K_M | RecommendedDefault | 64 GB | 68 GB | 73 GB |
| Q5_K_M | Very good | 76 GB | 80 GB | 85 GB |
| Q6_K | Near-lossless | 87 GB | 92 GB | 97 GB |
| Q8_0 | Practically lossless | 113 GB | 118 GB | 123 GB |
| BF16 | Full precision | 212 GB | 221 GB | 225 GB |
KV cache note: Standard grouped-query attention: 2 x 46 layers x 8 KV heads x 128 dims x 2 bytes = 188,416 bytes (184 KiB) per token, about 1.5GB at 8K and 24.7GB at the full 128K.
Performance
How fast GLM-4.5-Air runs
Single-user generation speed on popular GPUs that fit the model entirely in memory, at the best quantization each can hold.
RTX PRO 6000
Q5_K_M · 96GB
~80tok/s
RTX PRO 5000 72GB
Q4_K_M · 72GB
~73tok/s
M5 Ultra 512GB
Q8_0 · 512GB
~28tok/s
M5 Ultra 256GB
Q8_0 · 256GB
~28tok/s
M5 Max 128GB
Q5_K_M · 128GB
~25tok/s
M4 Max 128GB
Q5_K_M · 128GB
~23tok/s
M3 Ultra 512GB
Q8_0 · 512GB
~20tok/s
Ryzen AI Max+ 395
Q5_K_M · 128GB
~13tok/s
DGX Spark
Q6_K · 128GB
~12tok/s
Ryzen AI Max+ PRO 495
Q8_0 · 192GB
~9.3tok/s
Overview
About GLM-4.5-Air
GLM-4.5-Air is Z.ai's 106B mixture-of-experts with 12B active parameters, built for agentic coding and tool use with a switchable thinking mode. Z.ai's later releases went either much larger (the GLM-5 series) or smaller (GLM-4.7-Flash), so Air is still the GLM model aimed at 96GB to 128GB machines. It needs roughly 70GB at Q4_K_M with 8K context: a Mac or Strix Halo system with 96GB or more runs it fully in memory, and a 24GB GPU with 64GB of system RAM can run it with experts offloaded. Its full-attention KV cache is large, so long contexts cost more memory than on gpt-oss-120b or Qwen3.5 122B-A10B.
Strengths
- +Strong agentic coding and tool calling for its size
- +Toggleable thinking mode
- +12B active parameters keep it responsive on unified-memory machines
- +MIT license
Weaknesses
- −Needs roughly 70GB at Q4_K_M
- −Large KV cache (184 KiB per token) limits long contexts
- −Text only
- −Now trails gpt-oss-120b and Qwen3.5 122B-A10B on most benchmarks
Setup
How to run GLM-4.5-Air
$ llama-server -hf unsloth/GLM-4.5-Air-GGUF:Q4_K_M -c 8192 -ngl 99$ mlx_lm.chat --model mlx-community/GLM-4.5-Air-4bitWeights: zai-org/GLM-4.5-Air · GGUF: unsloth/GLM-4.5-Air-GGUF
Alternatives
Models like GLM-4.5-Air
OpenAI
gpt-oss-120b
117B (5.1B active) · 128K ctx
Alibaba Qwen
Qwen3.5 122B-A10B
122B (10B active) · 256K ctx
Z.ai
GLM-5.3-Flash
320B (18B active) · 1.0M ctx
Meta
Llama 4 Scout
109B (17B active) · 10.5M ctx
Frequently asked questions
How much VRAM do you need to run GLM-4.5-Air?
About 68GB at Q4_K_M with 8K tokens of context: 64.3GB of weights, 1.5GB of KV cache, and 2.5GB of runtime overhead. Higher-precision quants and longer contexts need more; see the table above.
What is the cheapest GPU that can run GLM-4.5-Air?
The smallest card in our database that can hold it is the RTX PRO 5000 72GB (72GB), at Q4_K_M with little memory to spare, generating ~73 tokens/sec.
Is GLM-4.5-Air free for commercial use?
GLM-4.5-Air is released under the MIT license. That is a permissive license, so commercial use is allowed.
How long a context does GLM-4.5-Air support?
Up to 131,072 tokens (128K). Long contexts need a lot of extra memory for the KV cache, so most local setups run 8K to 32K.
Sources: GLM-4.5-Air model card (Hugging Face), Unsloth GLM-4.5-Air GGUF files. Capability score basis: Placed between the Qwen3 32B and gpt-oss-120b anchors from its Artificial Analysis Intelligence Index v3 standing in reasoning mode (October 2025).