Mac Studio M3 Ultra 96GB vs RX 7800 XT 16GB for Local LLMs

The Mac Studio M3 Ultra 96GB has about 31% more memory bandwidth (819 vs 624 GB/s). Batch-1 decode tracks bandwidth closely, so a model that fits both cards should decode roughly 31% faster on the Mac Studio M3 Ultra 96GB. The Mac Studio M3 Ultra 96GB fits more of the catalog at Q4/8K — 47 vs 25 of 61 models (96 vs 16 GB VRAM). Largest model that fits the Mac Studio M3 Ultra 96GB but not the RX 7800 XT 16GB: DeepSeek-V4-Flash (158.1B). MSRP is $3,999 for the Mac Studio M3 Ultra 96GB vs $499 for the RX 7800 XT 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 Mac Studio M3 Ultra 96GB posts the higher tok/s in 35 rows vs 9. Methodology.

Spec comparison

	Mac Studio M3 Ultra 96GB	RX 7800 XT 16GB
Vendor	Apple	AMD
VRAM	96 GB	16 GB
Memory type	LPDDR5	GDDR6
Memory bandwidth	819 GB/s	624 GB/s
TDP	480 W	263 W
MSRP (list)	$3,999	$499
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)	Mac Studio M3 Ultra 96GB tok/s	Mac Studio M3 Ultra 96GB fits	RX 7800 XT 16GB tok/s	RX 7800 XT 16GB fits	Winner
Qwen3-0.6B	0.8	651.5 est.	Yes	496.4 est.	Yes	Mac Studio M3 Ultra 96GB
gemma-3-1b-it	1.0	521.2 est.	Yes	397.1 est.	Yes	Mac Studio M3 Ultra 96GB
Llama-3.2-1B-Instruct	1.2	434.3 est.	Yes	330.9 est.	Yes	Mac Studio M3 Ultra 96GB
Qwen3-30B-A3B	30.5	173.7 est.	Yes	286.6 est.	No	RX 7800 XT 16GB
Qwen3-Coder-30B-A3B-Instruct	30.5	173.7 est.	Yes	286.6 est.	No	RX 7800 XT 16GB
Qwen3-30B-A3B-Instruct-2507	30.5	173.7 est.	Yes	286.6 est.	No	RX 7800 XT 16GB
GLM-4.7-Flash	31.2	173.7 est.	Yes	275.1 est.	No	RX 7800 XT 16GB
Qwen3-1.7B	2.0	260.6 est.	Yes	198.5 est.	Yes	Mac Studio M3 Ultra 96GB
Qwen3-Next-80B-A3B-Instruct	81.3	173.7 est.	Yes	45.1 est.	No	Mac Studio M3 Ultra 96GB
Qwen3-Coder-Next	79.7	173.7 est.	Yes	46.9 est.	No	Mac Studio M3 Ultra 96GB
Llama-3.2-3B-Instruct	3.2	154.6 measured	Yes	124.1 est.	Yes	Mac Studio M3 Ultra 96GB
Phi-4-mini-instruct	3.8	137.2 est.	Yes	104.5 est.	Yes	Mac Studio M3 Ultra 96GB
Phi-4-mini-reasoning	3.8	137.2 est.	Yes	104.5 est.	Yes	Mac Studio M3 Ultra 96GB
gemma-3-4b-it	4.3	133.6 est.	Yes	101.8 est.	Yes	Mac Studio M3 Ultra 96GB
Qwen3-4B-Instruct-2507	4.0	130.3 est.	Yes	99.3 est.	Yes	Mac Studio M3 Ultra 96GB

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

	Mac Studio M3 Ultra 96GB	RX 7800 XT 16GB
Catalog models that fit	47 of 61	25 of 61
Largest exclusive fit	DeepSeek-V4-Flash (158.1B)	—

Mac Studio M3 Ultra 96GB details → · RX 7800 XT 16GB details →