Ryzen AI Max 390 64GB vs L40S 48GB for Local LLMs

The L40S 48GB has about 302% more memory bandwidth (864 vs 215 GB/s). Batch-1 decode tracks bandwidth closely, so a model that fits both cards should decode roughly 302% faster on the L40S 48GB. Both fit the same number of catalog models at Q4/8K (41 of 69; 48 vs 48 GB VRAM). MSRP is $1,300 for the Ryzen AI Max 390 64GB vs $8,000 for the L40S 48GB. 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 (57 shared models), the L40S 48GB posts the higher tok/s in 57 rows vs 0. Methodology.

Spec comparison

	Ryzen AI Max 390 64GB	L40S 48GB
Vendor	AMD	NVIDIA
VRAM	48 GB	48 GB
Memory type	LPDDR5X	GDDR6
Memory bandwidth	215 GB/s	864 GB/s
TDP	120 W	350 W
MSRP (list)	$1,300	$8,000
Buy	Search Amazon (affiliate)	Search Amazon (affiliate)

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 57 shared models

Model	Params (B)	Ryzen AI Max 390 64GB tok/s	Ryzen AI Max 390 64GB fits	L40S 48GB tok/s	L40S 48GB fits	Winner
MiniCPM5-1B	1.08	126.7 est.	Yes	509.1 est.	Yes	L40S 48GB
Qwen3.5-2B	2.0	68.4 est.	Yes	274.9 est.	Yes	L40S 48GB
DeepSeek-R1-0528-Qwen3-8B-layer-mix-bpw-3.8-mlx	2.3	59.5 est.	Yes	239.1 est.	Yes	L40S 48GB
Qwen3.6-35B-A3B	36.0	45.6 est.	Yes	183.3 est.	Yes	L40S 48GB
Qwen3.5-35B-A3B	34.7	45.6 est.	Yes	183.3 est.	Yes	L40S 48GB
GLM-4.7-Flash	31.2	45.6 est.	Yes	183.3 est.	Yes	L40S 48GB
Qwen3-30B-A3B-Instruct-2507	30.5	45.6 est.	Yes	183.3 est.	Yes	L40S 48GB
Nemotron-3-Nano-Omni-30B-A3B-Reasoning-BF16	30.0	45.6 est.	Yes	183.3 est.	Yes	L40S 48GB
Qwen3-Coder-Next	79.7	45.6 est.	Yes	183.3 est.	Yes	L40S 48GB
Ornith-1.0-35B	35.0	45.6 est.	Yes	183.3 est.	Yes	L40S 48GB
Qwen3-Next-80B-A3B-Instruct	81.3	45.6 est.	Yes	183.3 est.	Yes	L40S 48GB
qwen35b-a3b-fable-sft-abliterated	34.7	45.6 est.	Yes	183.3 est.	Yes	L40S 48GB
Llama-3.2-3B-Instruct	3.2	42.8 est.	Yes	171.8 est.	Yes	L40S 48GB
gpt-oss-20b	21.5	38.0 est.	Yes	152.7 est.	Yes	L40S 48GB
gpt-oss-120b	120.4	37.9 est.	No	152.2 est.	No	L40S 48GB

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

	Ryzen AI Max 390 64GB	L40S 48GB
Catalog models that fit	41 of 69	41 of 69
Largest exclusive fit	—	—

Ryzen AI Max 390 64GB details → · L40S 48GB details →