RX 7900 XT 20GB vs T4 16GB for Local LLMs

The RX 7900 XT 20GB has about 150% more memory bandwidth (800 vs 320 GB/s). Batch-1 decode tracks bandwidth closely, so a model that fits both cards should decode roughly 150% faster on the RX 7900 XT 20GB. The RX 7900 XT 20GB fits more of the catalog at Q4/8K — 32 vs 25 of 61 models (20 vs 16 GB VRAM). Largest model that fits the RX 7900 XT 20GB but not the T4 16GB: GLM-4.7-Flash (31.2B). MSRP is $899 for the RX 7900 XT 20GB vs $2,000 for the T4 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 (44 shared models), the RX 7900 XT 20GB posts the higher tok/s in 44 rows vs 0. Methodology.

Spec comparison

	RX 7900 XT 20GB	T4 16GB
Vendor	AMD	NVIDIA
VRAM	20 GB	16 GB
Memory type	GDDR6	GDDR6
Memory bandwidth	800 GB/s	320 GB/s
TDP	315 W	70 W
MSRP (list)	$899	$2,000
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 44 shared models

Model	Params (B)	RX 7900 XT 20GB tok/s	RX 7900 XT 20GB fits	T4 16GB tok/s	T4 16GB fits	Winner
Qwen3-0.6B	0.8	636.4 est.	Yes	254.5 est.	Yes	RX 7900 XT 20GB
gemma-3-1b-it	1.0	509.1 est.	Yes	203.6 est.	Yes	RX 7900 XT 20GB
Llama-3.2-1B-Instruct	1.2	424.2 est.	Yes	169.7 est.	Yes	RX 7900 XT 20GB
Qwen3-1.7B	2.0	254.5 est.	Yes	101.8 est.	Yes	RX 7900 XT 20GB
Qwen3-30B-A3B	30.5	169.7 est.	Yes	147.0 est.	No	RX 7900 XT 20GB
Qwen3-Coder-30B-A3B-Instruct	30.5	169.7 est.	Yes	147.0 est.	No	RX 7900 XT 20GB
GLM-4.7-Flash	31.2	169.7 est.	Yes	141.1 est.	No	RX 7900 XT 20GB
Qwen3-30B-A3B-Instruct-2507	30.5	169.7 est.	Yes	147.0 est.	No	RX 7900 XT 20GB
gpt-oss-20b	21.5	141.4 est.	Yes	56.6 est.	Yes	RX 7900 XT 20GB
Phi-4-mini-instruct	3.8	134.0 est.	Yes	53.6 est.	Yes	RX 7900 XT 20GB
Phi-4-mini-reasoning	3.8	134.0 est.	Yes	53.6 est.	Yes	RX 7900 XT 20GB
Llama-3.2-3B-Instruct	3.2	131.2 measured	Yes	63.6 est.	Yes	RX 7900 XT 20GB
gemma-3-4b-it	4.3	130.5 est.	Yes	52.2 est.	Yes	RX 7900 XT 20GB
Qwen3-4B-Instruct-2507	4.0	127.3 est.	Yes	50.9 est.	Yes	RX 7900 XT 20GB
Qwen3-4B-Thinking-2507	4.0	127.3 est.	Yes	50.9 est.	Yes	RX 7900 XT 20GB

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

	RX 7900 XT 20GB	T4 16GB
Catalog models that fit	32 of 61	25 of 61
Largest exclusive fit	GLM-4.7-Flash (31.2B)	—

RX 7900 XT 20GB details → · T4 16GB details →