RTX 5080 16GB vs RX 7700 XT 12GB for Local LLMs

The RTX 5080 16GB has about 122% more memory bandwidth (960 vs 432 GB/s). Batch-1 decode tracks bandwidth closely, so a model that fits both cards should decode roughly 122% faster on the RTX 5080 16GB. The RTX 5080 16GB fits more of the catalog at Q4/8K — 25 vs 18 of 61 models (16 vs 12 GB VRAM). Largest model that fits the RTX 5080 16GB but not the RX 7700 XT 12GB: gpt-oss-20b (21.5B). MSRP is $999 for the RTX 5080 16GB vs $449 for the RX 7700 XT 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 (40 shared models), the RTX 5080 16GB posts the higher tok/s in 34 rows vs 6. Methodology.

Spec comparison

	RTX 5080 16GB	RX 7700 XT 12GB
Vendor	NVIDIA	AMD
VRAM	16 GB	12 GB
Memory type	GDDR7	GDDR6
Memory bandwidth	960 GB/s	432 GB/s
TDP	360 W	245 W
MSRP (list)	$999	$449
Buy	NVIDIA GeForce RTX 5080 Founders Edition (affiliate) · More listings	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 40 shared models

Model	Params (B)	RTX 5080 16GB tok/s	RTX 5080 16GB fits	RX 7700 XT 12GB tok/s	RX 7700 XT 12GB fits	Winner
Qwen3-0.6B	0.8	763.6 est.	Yes	343.6 est.	Yes	RTX 5080 16GB
gemma-3-1b-it	1.0	610.9 est.	Yes	274.9 est.	Yes	RTX 5080 16GB
Llama-3.2-1B-Instruct	1.2	509.1 est.	Yes	229.1 est.	Yes	RTX 5080 16GB
Qwen3-30B-A3B	30.5	440.9 est.	No	111.6 est.	No	RTX 5080 16GB
Qwen3-Coder-30B-A3B-Instruct	30.5	440.9 est.	No	111.6 est.	No	RTX 5080 16GB
Qwen3-30B-A3B-Instruct-2507	30.5	440.9 est.	No	111.6 est.	No	RTX 5080 16GB
GLM-4.7-Flash	31.2	423.2 est.	No	107.1 est.	No	RTX 5080 16GB
Qwen3-1.7B	2.0	305.5 est.	Yes	137.5 est.	Yes	RTX 5080 16GB
gpt-oss-20b	21.5	204.9 measured	Yes	171.1 est.	No	RTX 5080 16GB
Llama-3.2-3B-Instruct	3.2	190.9 est.	Yes	85.9 est.	Yes	RTX 5080 16GB
Mistral-7B-Instruct-v0.3	7.2	163.6 measured	Yes	38.2 est.	Yes	RTX 5080 16GB
Phi-4-mini-instruct	3.8	160.8 est.	Yes	72.3 est.	Yes	RTX 5080 16GB
Phi-4-mini-reasoning	3.8	160.8 est.	Yes	72.3 est.	Yes	RTX 5080 16GB
gemma-3-4b-it	4.3	156.6 est.	Yes	70.5 est.	Yes	RTX 5080 16GB
Qwen3-4B-Instruct-2507	4.0	152.7 est.	Yes	68.7 est.	Yes	RTX 5080 16GB

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

	RTX 5080 16GB	RX 7700 XT 12GB
Catalog models that fit	25 of 61	18 of 61
Largest exclusive fit	gpt-oss-20b (21.5B)	—

RTX 5080 16GB details → · RX 7700 XT 12GB details →