llamaperf

M5 Ultra 512GB

APPLE · 512GB unified memory · 1 report

Engines people use on it: mlx-vlm 1 (reports)

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Reported performance on the M5 Ultra 512GB

These reports mix GPU counts and memory setups, so a model listed here may have needed extra cards or CPU offloading. The calculator estimates which models fit in 512 GB of unified memory.

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Apple hardware
generation:
71.1 tokens/s
prompt processing (prefill):
735.5 tokens/s
quant:
4bit (MLX)
mtp (multi-token prediction):
on

Reported by the source; GPU count, offloading and concurrent requests can change these figures. Prompt-processing speed is input throughput, not time to first token. Check the full setup before comparing.

User reports GLM-flash-4bit with MTP on an M5 Ultra 512GB, reaching 735.5 prompt t/s and 71.1 generation t/s at 131,072 prompt tokens. Setup is raw mlx-vlm with --prefill-step-size 8192. At 32,768 tokens the run gave 1056.0 prompt t/s and 72.7 generation t/s; at 65,536 tokens it gave 920.0 prompt t/s and 73.7 generation t/s. With --prefill-step-size 2048 the same trials gave 623.6 prompt t/s and 50.8 generation t/s at 131,072 tokens. The user also notes omlx with adaptive step size matched 8k performance from 2048 at 64k context and above.

Sep 25, 2026

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Reported configurations

Individual observations from this page, not expected speeds or a ranking. Select a model to open its report, with the source and offloading conditions. Reported context may be a limit rather than actual input length.

Model / hardwareQuant / engineReported contextGeneration
GLM-5.3 320B (18B active) Flash
M5 Ultra 512GB
4bit
mlx-vlm
131,07271.1 tokens/s