llamaperf

M4 16GB vs M4 Max 48GB for local LLMs

26 reports on the M4 16GB and 1 on the M4 Max 48GB

Which is faster for local LLMs?

On Qwen3.5 4B at 4-bit, the M4 16GB has 28.3 generation tokens/s (one run); prompt processing 352.4 tokens/s (one run); the M4 Max 48GB has 85.0 generation tokens/s (one run). Those are community reports whose engines and settings differ, so the gap is a rough sign, not a controlled measure of the two cards. Memory bandwidth, which caps how fast a card can write, is 4.6x higher on the M4 Max 48GB (120 GB/s on the M4 16GB, 546 on the M4 Max 48GB).

M4 16GB
Memory
16GB unified
Memory bandwidth
120 GB/s
FP16 compute
4.3 TFLOPS
Reports
26
M4 Max 48GB
Memory
48GB unified
Memory bandwidth
546 GB/s
FP16 compute
18.4 TFLOPS
Reports
1

Measured on both

Generation and prompt processing speeds from plain runs (one device, one request, no speculative decoding, the whole model in the device's memory) of the same model size at the same bit class. Each side shows the engines and reported context behind its median. Context can mean a configured window or prompt depth, so these are community comparisons with differing settings. How to read these

ModelM4 16GBM4 Max 48GB
Qwen3.5 4B4-bit28.3one runPP 352.4 (one run)llama.cppcontext not stated85.0one runllama.cppcontext not stated

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. Where a model was also measured above, the measurement wins.

ModelM4 16GBM4 Max 48GB
Qwen3.5 4B22.8 t/sQ8_045.5 t/sFP16
Qwen3.8 27Bdoesn't fit at these settings16.6 t/sQ6_K
Qwen3.8 125B · 6B activedoesn't fit at these settingsdoesn't fit at these settings
Qwen3.6 35B · 3B activedoesn't fit at these settings66.0 t/sQ5_K_M
DeepSeek V4 Flash 284B · 13B activedoesn't fit at these settingsdoesn't fit at these settings
Qwen3.6 27Bdoesn't fit at these settings16.6 t/sQ6_K
Gemma 4 26B · 4B activedoesn't fit at these settings32.3 t/sQ8_0

Change the context, RAM or model in the calculator: M4 16GB · M4 Max 48GB

Every report on each card, with its source: M4 16GB · M4 Max 48GB

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