llamaperf

M3 Max 48GB vs M4 Max 64GB for local LLMs

3 reports on the M3 Max 48GB and 18 on the M4 Max 64GB

Which is faster for local LLMs?

Nobody has reported the same model at the same quant on both cards yet, so there's no measured head-to-head. Memory bandwidth, which caps how fast a card can write, is 33% higher on the M4 Max 64GB (410 GB/s on the M3 Max 48GB, 546 on the M4 Max 64GB). The estimates below compare them on the models people run most.

M3 Max 48GB
Memory
48GB unified
Memory bandwidth
410 GB/s
FP16 compute
14.2 TFLOPS
Reports
3
M4 Max 64GB
Memory
64GB unified
Memory bandwidth
546 GB/s
FP16 compute
18.4 TFLOPS
Reports
18

Estimated by the calculator

The quant the calculator recommends for each card and its estimated speed at a 32,768-token context with 32 GB of system RAM, from memory bandwidth and the model's shape.

ModelM3 Max 48GBM4 Max 64GB
Qwen3.8 27B13.1 t/sQ6_K13.5 t/sQ8_0
Qwen3.8 125B · 6B activedoesn't fit at these settings61.4 t/sQ2_K
Qwen3.6 35B · 3B active52.2 t/sQ5_K_M42.5 t/sQ8_0
DeepSeek V4 Flash 284B · 13B activedoesn't fit at these settingsdoesn't fit at these settings
Qwen3.6 27B13.1 t/sQ6_K13.5 t/sQ8_0
Gemma 4 26B · 4B active25.5 t/sQ8_036.4 t/sQ8_0

Change the context, RAM or model in the calculator: M3 Max 48GB · M4 Max 64GB

Every report on each card, with its source: M3 Max 48GB · M4 Max 64GB

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