MacBook Pro M4 Max 128GB vs RX 7900 XT 20GB for Local LLMs

The RX 7900 XT 20GB has about 47% more memory bandwidth (800 vs 546 GB/s). Batch-1 decode tracks bandwidth closely, so a model that fits both cards should decode roughly 47% faster on the RX 7900 XT 20GB. The MacBook Pro M4 Max 128GB fits more of the catalog at Q4/8K — 47 vs 32 of 61 models (128 vs 20 GB VRAM). Largest model that fits the MacBook Pro M4 Max 128GB but not the RX 7900 XT 20GB: DeepSeek-V4-Flash (158.1B). MSRP is $4,399 for the MacBook Pro M4 Max 128GB vs $899 for the RX 7900 XT 20GB. 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 (46 shared models), the RX 7900 XT 20GB posts the higher tok/s in 38 rows vs 8. Methodology.

Spec comparison

	MacBook Pro M4 Max 128GB	RX 7900 XT 20GB
Vendor	Apple	AMD
VRAM	128 GB	20 GB
Memory type	LPDDR5X	GDDR6
Memory bandwidth	546 GB/s	800 GB/s
TDP	160 W	315 W
MSRP (list)	$4,399	$899
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 46 shared models

Model	Params (B)	MacBook Pro M4 Max 128GB tok/s	MacBook Pro M4 Max 128GB fits	RX 7900 XT 20GB tok/s	RX 7900 XT 20GB fits	Winner
Qwen3-0.6B	0.8	434.3 est.	Yes	636.4 est.	Yes	RX 7900 XT 20GB
gemma-3-1b-it	1.0	347.5 est.	Yes	509.1 est.	Yes	RX 7900 XT 20GB
Llama-3.2-1B-Instruct	1.2	289.5 est.	Yes	424.2 est.	Yes	RX 7900 XT 20GB
Qwen3-1.7B	2.0	173.7 est.	Yes	254.5 est.	Yes	RX 7900 XT 20GB
Qwen3-30B-A3B	30.5	115.8 est.	Yes	169.7 est.	Yes	RX 7900 XT 20GB
Qwen3-Coder-30B-A3B-Instruct	30.5	115.8 est.	Yes	169.7 est.	Yes	RX 7900 XT 20GB
GLM-4.7-Flash	31.2	115.8 est.	Yes	169.7 est.	Yes	RX 7900 XT 20GB
Qwen3-30B-A3B-Instruct-2507	30.5	115.8 est.	Yes	169.7 est.	Yes	RX 7900 XT 20GB
gpt-oss-20b	21.5	96.5 est.	Yes	141.4 est.	Yes	RX 7900 XT 20GB
Phi-4-mini-instruct	3.8	91.4 est.	Yes	134.0 est.	Yes	RX 7900 XT 20GB
Phi-4-mini-reasoning	3.8	91.4 est.	Yes	134.0 est.	Yes	RX 7900 XT 20GB
Llama-3.2-3B-Instruct	3.2	108.6 est.	Yes	131.2 measured	Yes	RX 7900 XT 20GB
gemma-3-4b-it	4.3	89.1 est.	Yes	130.5 est.	Yes	RX 7900 XT 20GB
Qwen3-4B-Instruct-2507	4.0	86.9 est.	Yes	127.3 est.	Yes	RX 7900 XT 20GB
Qwen3-4B-Thinking-2507	4.0	86.9 est.	Yes	127.3 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

	MacBook Pro M4 Max 128GB	RX 7900 XT 20GB
Catalog models that fit	47 of 61	32 of 61
Largest exclusive fit	DeepSeek-V4-Flash (158.1B)	—

MacBook Pro M4 Max 128GB details → · RX 7900 XT 20GB details →