llamaperf

M1 Max 64GB vs M1 Ultra 64GB for local LLMs

45 reports on the M1 Max 64GB and 4 on the M1 Ultra 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 2.0x higher on the M1 Ultra 64GB (410 GB/s on the M1 Max 64GB, 819 on the M1 Ultra 64GB). The estimates below compare them on the models people run most.

M1 Max 64GB
Memory
64GB unified
Memory bandwidth
410 GB/s
FP16 compute
10.4 TFLOPS
Reports
45
M1 Ultra 64GB
Memory
64GB unified
Memory bandwidth
819 GB/s
FP16 compute
21 TFLOPS
Reports
4

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.

ModelM1 Max 64GBM1 Ultra 64GB
Qwen3.8 27B10.0 t/sQ8_014.9 t/sQ8_0
Qwen3.8 125B · 6B active45.7 t/sQ2_K68.0 t/sQ2_K
Qwen3.6 35B · 3B active31.6 t/sQ8_047.1 t/sQ8_0
DeepSeek V4 Flash 284B · 13B activedoesn't fit at these settingsdoesn't fit at these settings
Qwen3.6 27B10.0 t/sQ8_014.9 t/sQ8_0
Gemma 4 26B · 4B active27.1 t/sQ8_040.4 t/sQ8_0

Change the context, RAM or model in the calculator: M1 Max 64GB · M1 Ultra 64GB

Every report on each card, with its source: M1 Max 64GB · M1 Ultra 64GB

More comparisons