Mac Studio M3 Ultra 96GB vs RX 7900 XTX 24GB for Local LLMs

The RX 7900 XTX 24GB has about 17% more memory bandwidth (960 vs 819 GB/s). Batch-1 decode tracks bandwidth closely, so a model that fits both cards should decode roughly 17% faster on the RX 7900 XTX 24GB. The Mac Studio M3 Ultra 96GB fits more of the catalog at Q4/8K — 47 vs 33 of 61 models (96 vs 24 GB VRAM). Largest model that fits the Mac Studio M3 Ultra 96GB but not the RX 7900 XTX 24GB: DeepSeek-V4-Flash (158.1B). MSRP is $3,999 for the Mac Studio M3 Ultra 96GB vs $999 for the RX 7900 XTX 24GB. 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 (47 shared models), the RX 7900 XTX 24GB posts the higher tok/s in 35 rows vs 12. Methodology.

Spec comparison

	Mac Studio M3 Ultra 96GB	RX 7900 XTX 24GB
Vendor	Apple	AMD
VRAM	96 GB	24 GB
Memory type	LPDDR5	GDDR6
Memory bandwidth	819 GB/s	960 GB/s
TDP	480 W	355 W
MSRP (list)	$3,999	$999
Buy	Search Amazon (affiliate)	ASRock Radeon RX 7900 XTX Phantom Gaming 24GB OC (affiliate) · More listings

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 47 shared models

Model	Params (B)	Mac Studio M3 Ultra 96GB tok/s	Mac Studio M3 Ultra 96GB fits	RX 7900 XTX 24GB tok/s	RX 7900 XTX 24GB fits	Winner
Qwen3-0.6B	0.8	651.5 est.	Yes	763.6 est.	Yes	RX 7900 XTX 24GB
gemma-3-1b-it	1.0	521.2 est.	Yes	610.9 est.	Yes	RX 7900 XTX 24GB
Llama-3.2-1B-Instruct	1.2	434.3 est.	Yes	509.1 est.	Yes	RX 7900 XTX 24GB
Qwen3-1.7B	2.0	260.6 est.	Yes	305.5 est.	Yes	RX 7900 XTX 24GB
Qwen3-30B-A3B	30.5	173.7 est.	Yes	203.6 est.	Yes	RX 7900 XTX 24GB
Qwen3-Coder-30B-A3B-Instruct	30.5	173.7 est.	Yes	203.6 est.	Yes	RX 7900 XTX 24GB
GLM-4.7-Flash	31.2	173.7 est.	Yes	203.6 est.	Yes	RX 7900 XTX 24GB
Qwen3-30B-A3B-Instruct-2507	30.5	173.7 est.	Yes	203.6 est.	Yes	RX 7900 XTX 24GB
Llama-3.2-3B-Instruct	3.2	154.6 measured	Yes	190.9 est.	Yes	RX 7900 XTX 24GB
Qwen3-Next-80B-A3B-Instruct	81.3	173.7 est.	Yes	156.2 est.	No	Mac Studio M3 Ultra 96GB
Qwen3-Coder-Next	79.7	173.7 est.	Yes	162.3 est.	No	Mac Studio M3 Ultra 96GB
gpt-oss-20b	21.5	115.5 measured	Yes	169.7 est.	Yes	RX 7900 XTX 24GB
Phi-4-mini-instruct	3.8	137.2 est.	Yes	160.8 est.	Yes	RX 7900 XTX 24GB
Phi-4-mini-reasoning	3.8	137.2 est.	Yes	160.8 est.	Yes	RX 7900 XTX 24GB
gemma-3-4b-it	4.3	133.6 est.	Yes	156.6 est.	Yes	RX 7900 XTX 24GB

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 7900 XTX 24GB
Catalog models that fit	47 of 61	33 of 61
Largest exclusive fit	DeepSeek-V4-Flash (158.1B)	—

Mac Studio M3 Ultra 96GB details → · RX 7900 XTX 24GB details →