Radeon RX 7900 XT Price & Used Prices: Which Local LLMs Can It Run?

• Memory20 GB · GDDR6
• Bandwidth800 GB/s
• FP16 / BF16103 TFLOPS
• INT8103 TOPS

Bus width

320-bit

Architecture

RDNA 3 (Navi 31)

Cores

5,376

Tensor cores

168

Ecosystem

ROCm

Interface

PCIe 4.0 x16

Power

315 W

Power connector

2× 8-pin

Length

276 mm

Type

Consumer

Launch date

Dec 13, 2022

MSRP

$899

1. 1

   Plan for context separately

   Whether this card is enough usually depends not on the model itself but on context: once a 27B model is loaded at 4-bit, just over 3GB is left for context. If you need longer context, use llama.cpp's -ctk / -ctv options to store the context cache as q8_0, which roughly halves its footprint, or switch to a 2-bit model.

2. 2

   Don't confuse it with the 7900 GRE

   The RX 7900 GRE has a similar name and the same chip, but only 16GB, which can't hold a 27B model at 4-bit; before buying, confirm it is the 20GB 7900 XT. The reference 7900 XT is 276 mm long, takes 2.5 slots and draws 315W, and AMD recommends a 750W power supply.

3. 3

   Software

   ROCm officially supports it on both Linux and Windows, and Ollama and llama.cpp recognize it directly, just as with the XTX. 20GB is most awkward in vLLM: AMD cards can't use AWQ or GPTQ, and the original BF16 version of a 27B model needs more than 50GB, so in practice this card mostly runs GGUF.

Spec	Radeon RX 7900 XT	Radeon RX 7900 XTX	GeForce RTX 3090	GeForce RTX 5070 Ti
Memory	20 GB	24 GB20% more	24 GB20% more	16 GB20% less
Bandwidth	800 GB/s	960 GB/s20% higher	936 GB/s17% higher	896 GB/s12% higher
BF16 / FP16 compute	103 TFLOPS	123 TFLOPS19% higher	142 TFLOPS38% higher	176 TFLOPS71% higher
INT8 compute	103 TOPS	123 TOPS19% higher	285 TOPS176% higher	352 TOPS241% higher
Qwen3.8 27B speed (2-bit)	56.1 t/s	66.3 t/s18% faster	64.8 t/s16% faster	62.3 t/s11% faster
Largest dense model (4-bit)	30B	37B23% more	37B23% more	23B23% less
Power	315 W	355 W13% higher	350 W11% higher	300 W5% lower
GPU interconnect	—	—	NVLink 112.5 GB/s	Not supported
Interface	PCIe 4.0 x16	PCIe 4.0 x16	PCIe 4.0 x16	PCIe 5.0 x16
Released	2022-12	2022-12	2020-09	2025-02
eBay median	$810Buy Radeon RX 7900 XT	$1,250Buy Radeon RX 7900 XTX	$1,799Buy GeForce RTX 3090	$1,365Buy GeForce RTX 5070 Ti

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