RTX 3070 8GB vs RX 7900 GRE 16GB for Local LLMs

The RX 7900 GRE 16GB has about 29% more memory bandwidth (576 vs 448 GB/s). Batch-1 decode tracks bandwidth closely, so a model that fits both cards should decode roughly 29% faster on the RX 7900 GRE 16GB. The RX 7900 GRE 16GB fits more of the catalog at Q4/8K — 25 vs 17 of 61 models (16 vs 8 GB VRAM). Largest model that fits the RX 7900 GRE 16GB but not the RTX 3070 8GB: gpt-oss-20b (21.5B). MSRP is $499 for the RTX 3070 8GB vs $549 for the RX 7900 GRE 16GB. 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 (38 shared models), the RX 7900 GRE 16GB posts the higher tok/s in 37 rows vs 1. Methodology.

Spec comparison

	RTX 3070 8GB	RX 7900 GRE 16GB
Vendor	NVIDIA	AMD
VRAM	8 GB	16 GB
Memory type	GDDR6	GDDR6
Memory bandwidth	448 GB/s	576 GB/s
TDP	220 W	260 W
MSRP (list)	$499	$549
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 38 shared models

Model	Params (B)	RTX 3070 8GB tok/s	RTX 3070 8GB fits	RX 7900 GRE 16GB tok/s	RX 7900 GRE 16GB fits	Winner
Qwen3-0.6B	0.8	356.4 est.	Yes	458.2 est.	Yes	RX 7900 GRE 16GB
gemma-3-1b-it	1.0	285.1 est.	Yes	366.5 est.	Yes	RX 7900 GRE 16GB
Llama-3.2-1B-Instruct	1.2	237.6 est.	Yes	305.5 est.	Yes	RX 7900 GRE 16GB
Qwen3-30B-A3B	30.5	51.4 est.	No	264.5 est.	No	RX 7900 GRE 16GB
Qwen3-Coder-30B-A3B-Instruct	30.5	51.4 est.	No	264.5 est.	No	RX 7900 GRE 16GB
Qwen3-30B-A3B-Instruct-2507	30.5	51.4 est.	No	264.5 est.	No	RX 7900 GRE 16GB
GLM-4.7-Flash	31.2	49.4 est.	No	253.9 est.	No	RX 7900 GRE 16GB
Qwen3-1.7B	2.0	142.5 est.	Yes	183.3 est.	Yes	RX 7900 GRE 16GB
Llama-3.2-3B-Instruct	3.2	89.1 est.	Yes	114.5 est.	Yes	RX 7900 GRE 16GB
gpt-oss-20b	21.5	78.9 est.	No	101.8 est.	Yes	RX 7900 GRE 16GB
Phi-4-mini-instruct	3.8	75.0 est.	Yes	96.5 est.	Yes	RX 7900 GRE 16GB
Phi-4-mini-reasoning	3.8	75.0 est.	Yes	96.5 est.	Yes	RX 7900 GRE 16GB
gemma-3-4b-it	4.3	73.1 est.	Yes	94.0 est.	Yes	RX 7900 GRE 16GB
Qwen3-4B-Instruct-2507	4.0	71.3 est.	Yes	91.6 est.	Yes	RX 7900 GRE 16GB
Qwen3-4B-Thinking-2507	4.0	71.3 est.	Yes	91.6 est.	Yes	RX 7900 GRE 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 3070 8GB	RX 7900 GRE 16GB
Catalog models that fit	17 of 61	25 of 61
Largest exclusive fit	—	gpt-oss-20b (21.5B)

RTX 3070 8GB details → · RX 7900 GRE 16GB details →