llamaperf

Intel Arc B580 12GB vs M4 32GB for local LLMs

10 reports on the Intel Arc B580 12GB and 14 on the M4 32GB

Which is faster for local LLMs?

On Qwen3 4B at 4-bit, the Intel Arc B580 12GB has 12.7 generation tokens/s (one run); prompt processing 260.5 tokens/s (one run); the M4 32GB has 36.2 generation tokens/s (one run); prompt processing 416.6 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 3.8x higher on the Intel Arc B580 12GB (456 GB/s on the Intel Arc B580 12GB, 120 on the M4 32GB).

Intel Arc B580 12GB
Memory
12GB
Memory bandwidth
456 GB/s
FP16 compute
117 TFLOPS
Reports
10
M4 32GB
Memory
32GB unified
Memory bandwidth
120 GB/s
FP16 compute
4.3 TFLOPS
Reports
14

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

ModelIntel Arc B580 12GBM4 32GB
Qwen3 4B4-bit12.7one runPP 260.5 (one run)llama.cppcontext not stated36.2one runPP 416.6 (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.

ModelIntel Arc B580 12GBM4 32GB
Qwen3 4B77.2 t/sQ6_K11.4 t/sFP16
Qwen3.8 27B1.6 t/sQ8_0, layers on CPU6.8 t/sQ4_K_S
Qwen3.8 125B · 6B activedoesn't fit at these settingsdoesn't fit at these settings
Qwen3.6 35B · 3B active13.7 t/sQ6_K, experts in RAM24.6 t/sQ3_K_M
DeepSeek V4 Flash 284B · 13B activedoesn't fit at these settingsdoesn't fit at these settings
Qwen3.6 27B1.6 t/sQ8_0, layers on CPU6.8 t/sQ4_K_S
Gemma 4 26B · 4B active74.5 t/sQ2_K14.9 t/sQ4_K_M

Change the context, RAM or model in the calculator: Intel Arc B580 12GB · M4 32GB

Every report on each card, with its source: Intel Arc B580 12GB · M4 32GB

More comparisons