llamaperf

M3 Max 128GB vs M4 Max 128GB for local LLMs

6 reports on the M3 Max 128GB and 53 on the M4 Max 128GB

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 128GB (410 GB/s on the M3 Max 128GB, 546 on the M4 Max 128GB). The estimates below compare them on the models people run most.

M3 Max 128GB
Memory
128GB unified
Memory bandwidth
410 GB/s
FP16 compute
14.2 TFLOPS
Reports
6
M4 Max 128GB
Memory
128GB unified
Memory bandwidth
546 GB/s
FP16 compute
18.4 TFLOPS
Reports
53

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 128GBM4 Max 128GB
Qwen3.8 27B5.3 t/sFP166.7 t/sFP16
Qwen3.8 125B · 6B active24.3 t/sQ5_K_S30.7 t/sQ5_K_S
Qwen3.6 35B · 3B active16.8 t/sFP1621.2 t/sFP16
DeepSeek V4 Flash 284B · 13B active38.2 t/sQ2_K48.3 t/sQ2_K
Qwen3.6 27B5.3 t/sFP166.7 t/sFP16
Gemma 4 26B · 4B active14.4 t/sFP1618.2 t/sFP16

Change the context, RAM or model in the calculator: M3 Max 128GB · M4 Max 128GB

Every report on each card, with its source: M3 Max 128GB · M4 Max 128GB

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