llamaperf

M5 Max 48GB vs AMD RX 6700 XT for local LLMs

66 reports on the M5 Max 48GB and 4 on the AMD RX 6700 XT

Which is faster for local LLMs?

On Qwen3 8B at 4-bit, the M5 Max 48GB has 104.2 generation tokens/s (2 runs); prompt processing 2947.6 tokens/s (2 runs); the AMD RX 6700 XT has 61.0 generation tokens/s (one run); prompt processing 851.0 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 1.6x higher on the M5 Max 48GB (614 GB/s on the M5 Max 48GB, 384 on the AMD RX 6700 XT).

M5 Max 48GB
Memory
48GB unified
Memory bandwidth
614 GB/s
FP16 compute
not on record
Reports
66
AMD RX 6700 XT
Memory
12GB
Memory bandwidth
384 GB/s
FP16 compute
26.4 TFLOPS
Reports
4

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

ModelM5 Max 48GBAMD RX 6700 XT
Qwen3 8B4-bit104.22 runsPP 2947.6 (2 runs)llama.cpp, MLXcontext not stated61.0one runPP 851.0 (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.

ModelM5 Max 48GBAMD RX 6700 XT
Qwen3 8B30.5 t/sFP1660.3 t/sQ3_K_M
Qwen3.8 27B22.3 t/sQ6_K1.6 t/sQ8_0, layers on CPU
Qwen3.8 125B · 6B activedoesn't fit at these settingsdoesn't fit at these settings
Qwen3.6 35B · 3B active88.4 t/sQ5_K_M13.3 t/sQ6_K, experts in RAM
DeepSeek V4 Flash 284B · 13B activedoesn't fit at these settingsdoesn't fit at these settings
Qwen3.6 27B22.3 t/sQ6_K1.6 t/sQ8_0, layers on CPU
Gemma 4 26B · 4B active43.2 t/sQ8_062.7 t/sQ2_K

Change the context, RAM or model in the calculator: M5 Max 48GB · AMD RX 6700 XT

Every report on each card, with its source: M5 Max 48GB · AMD RX 6700 XT

More comparisons