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Can the Apple M3 Ultra (256GB) run GLM-5.3 Flash 320B-A18B?

Apple M3 Ultra (256GB) × GLM-5.3 Flash 320B-A18B8K context
Yes, with heavy quantizationFits only at a low-quality quant
Memory at Q3_K_M157.6 GB of 192 GB
Weights 156.9 GBKV cache 0.1 GBRuntime 0.6 GB
QuantQ3_K_MNoticeably degraded
Speed~56tokens per second
Max context1024Kthe model's full window
  1. FP16
  2. Q8_0
  3. Q6_K
  4. Q5_K_M
  5. Q4_K_M
  6. Q3_K_M
  7. Q2_K

Only just. GLM-5.3 Flash 320B-A18B fits on the Apple M3 Ultra (256GB) at Q3_K_M, which costs noticeable quality. Expect about 56 tokens/second. A card with more memory is a better experience.

Try other context lengths

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Memory needed by quantization

At 8,192 tokens of context. The black line marks the 192 GB the Apple M3 Ultra (256GB) can use. macOS lets the GPU use about 192 GB of the 256 GB unified memory by default.

QuantQualityMemoryFits?Speed
FP16Full quality642.7 GBToo big—
Q8_0Near-lossless341.8 GBToo big—
Q6_KExcellent263.9 GBToo big—
Q5_K_MVery good229 GBToo big—
Q4_K_MGood, most popular195.3 GBToo big—
Q3_K_MNoticeably degraded157.6 GBFits~56 tok/s
Q2_KHeavily degraded121.1 GBFits~73 tok/s

Measured speed from real Apple M3 Ultra (256GB) owners

Tokens per second that people measured on their own Apple M3 Ultra (256GB), next to our estimate.

No one has measured GLM-5.3 Flash 320B-A18B on the Apple M3 Ultra (256GB) yet. The speeds above are estimates. Run the benchmark and yours becomes the first real number on this page.

Have an Apple M3 Ultra (256GB)? Add your real speed

One command times GLM-5.3 Flash 320B-A18B in your own Ollama, shows you exactly what it would send, and asks before sending anything. No sign-up, no personal data.

macOS and Linux

curl -fsSL https://gpufit.dev/bench.sh | sh

Windows (PowerShell)

irm https://gpufit.dev/bench.ps1 | iex

How the benchmark works

Models that run well on the Apple M3 Ultra (256GB)

Frequently asked questions

Can Apple M3 Ultra (256GB) run GLM-5.3 Flash 320B-A18B?

Only just. GLM-5.3 Flash 320B-A18B fits on the Apple M3 Ultra (256GB) at Q3_K_M, which costs noticeable quality. Expect about 56 tokens/second. A card with more memory is a better experience.

How much VRAM does GLM-5.3 Flash 320B-A18B need?

About 195.3 GB at Q4_K_M with 8,192 tokens of context, and about 642.7 GB at full FP16 precision.

How fast is GLM-5.3 Flash 320B-A18B on the Apple M3 Ultra (256GB)?

Roughly 56 tokens per second at Q3_K_M, estimated from the Apple M3 Ultra (256GB)'s 819 GB/s memory bandwidth.