llamaperf

M4 16GB vs M5 Max 128GB for local LLMs

26 reports on the M4 16GB and 49 on the M5 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 5.1x higher on the M5 Max 128GB (120 GB/s on the M4 16GB, 614 on the M5 Max 128GB). The estimates below compare them on the models people run most.

M4 16GB
Memory
16GB unified
Memory bandwidth
120 GB/s
FP16 compute
4.3 TFLOPS
Reports
26
M5 Max 128GB
Memory
128GB unified
Memory bandwidth
614 GB/s
FP16 compute
not on record
Reports
49

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.

ModelM4 16GBM5 Max 128GB
Qwen3.8 27Bdoesn't fit at these settings9.0 t/sFP16
Qwen3.8 125B · 6B activedoesn't fit at these settings41.2 t/sQ5_K_S
Qwen3.6 35B · 3B activedoesn't fit at these settings28.5 t/sFP16
DeepSeek V4 Flash 284B · 13B activedoesn't fit at these settings64.8 t/sQ2_K
Qwen3.6 27Bdoesn't fit at these settings9.0 t/sFP16
Gemma 4 26B · 4B activedoesn't fit at these settings24.4 t/sFP16

Change the context, RAM or model in the calculator: M4 16GB · M5 Max 128GB

Every report on each card, with its source: M4 16GB · M5 Max 128GB

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