HomeCan I run it?GLM-4.5-AirGLM-4.5-Air on a Mac Studio 256GB
Yes. GLM-4.5-Air at Q8_0 needs about 136.0 GB, and the Mac Studio M5 Ultra 256GB has 192.0 GB usable at a ~4k context.
Can I run GLM-4.5-Air on a Mac Studio 256GB?
GLM-4.5-Air at Q8_0 needs about 136.0 GB, and the Mac Studio M5 Ultra 256GB has 192.0 GB usable. That figure is 256 GB of unified memory on the spec sheet, of which 192.0 GB is usable for weights and cache, at 1200 GB/s memory bandwidth. Zhipu’s GLM-4.5-Air, a large model in the roughly 80 GB Q4 class — above a 24 GB card, below full DeepSeek-R1. These are estimates from our formula, not measured benchmarks.
- Quant that fits
- Q8_0 Fits with headroom
- Memory needed
- 136.0 GB at Q8_0, ~4k context
- Usable unified memory
- 192.0 GB of 256 GB unified memory
- Est. tokens/sec
- up to 75 estimate
Memory at each quant
| Quant | Need vs 192.0 GB | Verdict |
|---|---|---|
| Q4_K_M | 78.0 GB | Q4Fits |
| Q8_0 | 136.0 GB | Q8Fits |
| FP16 | 255.1 GB | FP16Won’t fit |
Estimated tokens per second
Estimate: up to 75 tokens/sec at Q8_0 (upper bound: this is a Mixture-of-Experts, and only the active weights are counted). This is a bandwidth-derived range, not a bench. Efficiency is a 45–80% unified-memory band from How we calculate.
Context headroom
At Q8_0, this machine has headroom out to about 128k tokens under our KV estimate. Longer chats need more memory for the cache. Figures assume an FP16 KV cache.
| Context | KV cache (FP16) | Total at Q8_0 | Verdict |
|---|---|---|---|
| 4k | 0.8 GB | 136.0 GB | Fits |
| 8k | 1.5 GB | 136.8 GB | Fits |
| 16k | 3.1 GB | 138.3 GB | Fits |
| 32k | 6.2 GB | 141.4 GB | Fits |
| 64k | 12.3 GB | 147.6 GB | Fits |
| 128k | 24.7 GB | 159.9 GB | Fits |
What to do instead
- Full hardware list: GLM-4.5-Air. Specs for this machine: Mac Studio M5 Ultra 256GB.
Other hardware for GLM-4.5-Air
- GLM-4.5-Air on an RTX 4090Won’t fit
- GLM-4.5-Air on an RTX 5090Won’t fit
- GLM-4.5-Air on dual RTX 3090sWon’t fit
- GLM-4.5-Air on a Mac mini 64GBWon’t fit
- GLM-4.5-Air on an RTX 3090Won’t fit
Other models on a Mac Studio 256GB
- Llama 3.3 70B on a Mac Studio 256GBFits
- R1 Distill 70B on a Mac Studio 256GBFits
- gpt-oss-120b on a Mac Studio 256GBFits
- Qwen3-235B on a Mac Studio 256GBFits
- DeepSeek-R1 on a Mac Studio 256GBWon’t fit
- DeepSeek-V3.2 on a Mac Studio 256GBWon’t fit
Quick answers
- Can I run GLM-4.5-Air on a Mac Studio 256GB?
- Yes. GLM-4.5-Air at Q8_0 needs about 136.0 GB, and the Mac Studio M5 Ultra 256GB has 192.0 GB usable.
- How much VRAM does GLM-4.5-Air need?
- About 78.0 GB at Q4_K_M, 136.0 GB at Q8_0 and 255.1 GB at FP16, estimated for a ~4k context.
- How fast is GLM-4.5-Air on a Mac Studio 256GB?
- Our estimate is up to 75 tokens per second at Q8_0, as an upper bound for this MoE. It is not a measured benchmark.
- What context length can I use?
- At Q8_0, our KV estimate supports up to about 128k tokens before the cache pushes the total over usable memory.