MacBook Neo A18 Pro 8GB vs Arc B580 12GB for Local LLMs

The Arc B580 12GB has about 660% more memory bandwidth (456 vs 60 GB/s). Batch-1 decode tracks bandwidth closely, so a model that fits both cards should decode roughly 660% faster on the Arc B580 12GB. The Arc B580 12GB fits more of the catalog at Q4/8K — 20 vs 11 of 67 models (12 vs 8 GB VRAM). Largest model that fits the Arc B580 12GB but not the MacBook Neo A18 Pro 8GB: Qwen3-14B (14.8B). MSRP is $0 for the MacBook Neo A18 Pro 8GB vs $249 for the Arc B580 12GB. MSRP is a launch list price, not live retail — Amazon prices move; click through for the current price. In the Q4/8K head-to-head below (36 shared models), the Arc B580 12GB posts the higher tok/s in 36 rows vs 0. Methodology.

Spec comparison

	MacBook Neo A18 Pro 8GB	Arc B580 12GB
Vendor	Apple	Intel
VRAM	8 GB	12 GB
Memory type	LPDDR5X	GDDR6
Memory bandwidth	60 GB/s	456 GB/s
TDP	20 W	190 W
MSRP (list)	$0	$249
Buy	Search Amazon	Search Amazon · eBay · Newegg · B&H Photo

MSRP is the launch list price, not live retail. Buy links are Amazon affiliate links — the price after you click is the live price.

Q4 / 8K head-to-head — top 15 of 36 shared models

Model	Params (B)	MacBook Neo A18 Pro 8GB tok/s	MacBook Neo A18 Pro 8GB fits	Arc B580 12GB tok/s	Arc B580 12GB fits	Winner
MiniCPM5-1B	1.08	70.0 est.	Yes	391.5 est.	Yes	Arc B580 12GB
Qwen3.5-2B	2.0	37.8 est.	Yes	211.4 est.	Yes	Arc B580 12GB
gpt-oss-20b	21.5	5.7 est.	No	172.1 est.	No	Arc B580 12GB
gemma-4-26B-A4B-it	25.2	3.9 est.	No	121.2 est.	No	Arc B580 12GB
Nemotron-3-Nano-Omni-30B-A3B-Reasoning-BF16	30.0	3.5 est.	No	111.2 est.	No	Arc B580 12GB
Nanbeige4.2-3B	4.0	19.2 est.	Yes	107.6 est.	Yes	Arc B580 12GB
Qwen3-4B-Instruct-2507	4.0	18.9 est.	Yes	105.7 est.	Yes	Arc B580 12GB
NVIDIA-Nemotron-3-Nano-4B-BF16	4.0	18.9 est.	Yes	105.7 est.	Yes	Arc B580 12GB
Qwen3-4B-Thinking-2507	4.0	18.9 est.	Yes	105.7 est.	Yes	Arc B580 12GB
Qwen3-30B-A3B-Instruct-2507	30.5	3.3 est.	No	104.2 est.	No	Arc B580 12GB
Qwen3.5-35B-A3B	34.7	2.8 est.	No	87.5 est.	No	Arc B580 12GB
Ornith-1.0-35B	35.0	2.7 est.	No	86.1 est.	No	Arc B580 12GB
gemma-4-E2B-it	5.1	14.8 est.	Yes	82.9 est.	Yes	Arc B580 12GB
Qwen3.6-35B-A3B	36.0	2.6 est.	No	81.8 est.	No	Arc B580 12GB
GLM-4.7-Flash	31.2	2.5 est.	No	81.2 est.	No	Arc B580 12GB

est. = bandwidth-based estimate; measured = curated real benchmark that overrides the estimate. Fits = weights + KV(8K) + 1 GB overhead ≤ 95% of VRAM.

Fit coverage at Q4 / 8K

	MacBook Neo A18 Pro 8GB	Arc B580 12GB
Catalog models that fit	11 of 67	20 of 67
Largest exclusive fit	—	Qwen3-14B (14.8B)

MacBook Neo A18 Pro 8GB details → · Arc B580 12GB details →