llamaperf

M3 Max 128GB vs M5 Max 48GB for local LLMs

6 reports on the M3 Max 128GB and 67 on the M5 Max 48GB

Which is faster for local LLMs?

On Qwen3.5 35B · 3B active at 4-bit, the M3 Max 128GB has 90.8 generation tokens/s (one run); the M5 Max 48GB has 111.2 generation tokens/s (one run); prompt processing 3378.3 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 50% higher on the M5 Max 48GB (410 GB/s on the M3 Max 128GB, 614 on the M5 Max 48GB).

M3 Max 128GB
Memory
128GB unified
Memory bandwidth
410 GB/s
FP16 compute
14.2 TFLOPS
Reports
6
M5 Max 48GB
Memory
48GB unified
Memory bandwidth
614 GB/s
FP16 compute
not on record
Reports
67

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

ModelM3 Max 128GBM5 Max 48GB
Qwen3.5 35B · 3B active4-bit90.8one runoMLXcontext not stated111.2one runPP 3378.3 (one run)llama.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.

ModelM3 Max 128GBM5 Max 48GB
Qwen3.5 35B · 3B active16.8 t/sFP1688.4 t/sQ5_K_M
Qwen3.8 27B5.3 t/sFP1622.3 t/sQ6_K
Qwen3.8 125B · 6B active24.3 t/sQ5_K_Sdoesn't fit at these settings
Qwen3.6 35B · 3B active16.8 t/sFP1688.4 t/sQ5_K_M
DeepSeek V4 Flash 284B · 13B active38.2 t/sQ2_Kdoesn't fit at these settings
Qwen3.6 27B5.3 t/sFP1622.3 t/sQ6_K
Gemma 4 26B · 4B active14.4 t/sFP1643.2 t/sQ8_0

Change the context, RAM or model in the calculator: M3 Max 128GB · M5 Max 48GB

Every report on each card, with its source: M3 Max 128GB · M5 Max 48GB

More comparisons