Can I Run GLM-4.5 on a Apple M5 Ultra (256GB)?
Runs at Q5_K_M — good quality with reasonable headroom.
2 quantizations fit your 256GB
| Quant | Min VRAM | Recommended | File size | Headroom |
|---|---|---|---|---|
| Q5_K_MBEST | 255.2 GB | 256.7 GB | 254.2 GB | +0.8 GB |
| Q4_K_M | 218.0 GB | 219.5 GB | 217.0 GB | +38.0 GB |
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Top-ranked open-source models that fit in 256GB.
FAQ
Can the Apple M5 Ultra (256GB) run GLM-4.5?
Yes. The Apple M5 Ultra (256GB)'s 256GB of unified memory is enough to run GLM-4.5 at Q5_K_M quantization (255.2GB required).
What's the best quantization to use?
Q5_K_M is the highest-precision quantization that fits in your 256GB. It uses about 255.2GB of memory and 256.7GB recommended for comfortable inference.
What if I need more headroom for context length?
KV cache memory grows with context length. The numbers above assume a baseline 2K-4K context. For long-context use (32K+), add another 2-6GB depending on the model architecture.