20GB VRAM

Radeon RX 7900 XT — what LLMs can it run?

73 of 110 indexed models fit comfortably in 20GB at 4K context, each at the highest-quality quant that still leaves headroom.

The short answer for Radeon RX 7900 XT

20 GB, 800 GB/s GDDR6. 73 of 110 models in this index fit comfortably at 4K context; 83 load at all.

Biggest that fits
Qwen2.5 32B Instruct — 17.5 GB at Q3_K_M — 2.5 GB spare at 4K, so longer context comes out of a thin margin.
Room to grow
DeepSeek-V2-Lite Chat — 10.1 GB at Q4_K_M — under 60% of the card, which leaves 9.9 GB for a long context window or a second process.
Speed ceiling
Llama 3.1 8B Instruct at Q4_K_M reads 4.6 GB of weights per token, so 800 GB/s puts a hard ceiling near 173 tok/s. That is arithmetic on two published numbers, not a benchmark — real throughput lands below it. No run on this card has been measured here, so there is nothing to compare the ceiling against.
The wall you will hit
Backend coverage, not capacity. At 800 GB/s the memory system is competitive with NVIDIA cards of the same size; what varies is whether your runtime has a working ROCm build for your kernel and card. llama.cpp and vLLM both ship official ROCm support — this is a setup question, not a hardware ceiling.

32B · 16

Radeon RX 7900 XT — what LLMs can it run? — 32B
ModelQuantEst. VRAMHeadroomtok/s
Qwen2.5 32B Instruct32BQ3_K_M17.53 GB+2.5 GB28–37Derived
DeepSeek-R1-Distill-Qwen-32B32BQ3_K_M17.53 GB+2.5 GB28–37Derived
Qwen3 30B-A3B Instruct30B-A3BAWQ INT416.35 GB+3.6 GB≤561Ceiling
Qwen3-Coder 30B-A3B Instruct30B-A3BAWQ INT416.35 GB+3.6 GB≤561Ceiling
Qwen3-VL 30B-A3B Instruct30B-A3BAWQ INT416.35 GB+3.6 GB≤561Ceiling
Qwen3.8 27B27BQ4_K_M17.47 GB+2.5 GB27–35Derived
Gemma 3 27B IT27BAWQ INT415.33 GB+4.7 GB≤61Ceiling
Gemma 2 27B Instruct27BAWQ INT415.79 GB+4.2 GB≤62Ceiling
Gemma 4 26B-A4B IT26B-A4BQ4_K_M16.39 GB+3.6 GB≤347Ceiling
Mistral Small 24B Instruct24BQ4_K_M15.89 GB+4.1 GB30–40Derived
LFM2.5 24B-A2B24B-A2BQ4_K_M15.27 GB+4.7 GB≤567Ceiling
Devstral Small 1.1 24B24BQ4_K_M15.64 GB+4.4 GB31–41Derived
Magistral Small 1.2 24B24BQ4_K_M15.64 GB+4.4 GB31–41Derived
Codestral 22B22BQ4_K_M15.03 GB+5 GB33–43Derived
ERNIE 4.5 21B-A3B21B-A3BQ4_K_M14.05 GB+5.9 GB≤463Ceiling
GPT-OSS 20B21B MoEMXFP412.76 GB+7.2 GB≤404Ceiling

14B · 18

Radeon RX 7900 XT — what LLMs can it run? — 14B
ModelQuantEst. VRAMHeadroomtok/s
InternLM2 20B Chat20BQ5_K_M15.59 GB+4.4 GB31–41Derived
DeepSeek-Coder-V2-Lite Instruct16B-A2.4BQ8_017.56 GB+2.4 GB≤330Ceiling
DeepSeek-V2-Lite Chat16B-A2.4BQ4_K_M10.08 GB+9.9 GB≤579Ceiling
StarCoder2 15B15BQ4_K_M10.19 GB+9.8 GB48–64Derived
Qwen3 14B Instruct14BQ5_K_M11.65 GB+8.4 GB42–56Derived
Qwen2.5 14B Instruct14BQ5_K_M11.73 GB+8.3 GB42–56Derived
DeepSeek-R1-Distill-Qwen-14B14BQ4_K_M10.14 GB+9.9 GB49–65Derived
Phi-4 14B14BQ5_K_M11.77 GB+8.2 GB42–56Derived
Phi-3 Medium 14B Instruct14BQ6_K12.86 GB+7.1 GB38–51Derived
Mistral Nemo 12B Instruct12BQ6_K11.14 GB+8.9 GB44–58Derived
Gemma 3 12B IT12BQ5_K_M9.84 GB+10.2 GB51–67Derived
Mellum2.1 12B-A2.5B Thinking12B-A2.5BQ8_013.6 GB+6.4 GB≤317Ceiling
Stable LM 2 12B Chat12BQ4_K_M8.35 GB+11.7 GB60–79Derived
Llama 3.2 11B Vision Instruct11BQ8_012.9 GB+7.1 GB38–50Derived
Solar 10.7B Instruct11BQ4_K_M7.6 GB+12.4 GB68–90Derived
Falcon 3 10B Instruct10BQ4_K_M7.28 GB+12.7 GB70–92Derived
Gemma 2 9B Instruct9BQ8_011.7 GB+8.3 GB45–59Derived
Qwen3.5 9B9BQ8_010.37 GB+9.6 GB45–59Derived

7B · 25

Radeon RX 7900 XT — what LLMs can it run? — 7B
ModelQuantEst. VRAMHeadroomtok/s
GLM-4-9B-Chat9BQ8_010.16 GB+9.8 GB46–61Derived
Qwen3-VL 8B Instruct8BQ8_010.39 GB+9.6 GB47–62Derived
Granite 4.2 8B8BQ8_010.45 GB+9.6 GB47–62Derived
Ministral 3 8B Instruct8BQ8_010.02 GB+10 GB49–64Derived
Qwen2-VL 7B Instruct7BQ4_K_M5.49 GB+14.5 GB88–116Derived
Granite 3.1 8B Instruct8BQ4_K_M5.88 GB+14.1 GB89–117Derived
Qwen3 8B Instruct8BQ6_K7.64 GB+12.4 GB66–87Derived
Llama 3.1 8B Instruct8BQ8_09.47 GB+10.5 GB52–68Derived
Nous Hermes 3 Llama 3.1 8B8BQ4_K_M5.64 GB+14.4 GB90–120Derived
Aya 23 8B8BQ4_K_M5.64 GB+14.4 GB90–120Derived
OpenChat 3.6 8B8BQ4_K_M5.64 GB+14.4 GB90–120Derived
DeepSeek-R1-Distill-Llama-8B8BQ5_K_M6.51 GB+13.5 GB77–102Derived
InternLM2 7B Chat7BQ4_K_M5.45 GB+14.6 GB94–124Derived
Qwen2.5 7B Instruct7BQ6_K6.77 GB+13.2 GB70–93Derived
Qwen2.5-Coder 7B Instruct7BQ4_K_M5.07 GB+14.9 GB95–126Derived
DeepSeek-R1-Distill-Qwen-7B7BQ4_K_M5.07 GB+14.9 GB95–126Derived
Gemma 4 E4B ITE4BQ8_08.46 GB+11.5 GB55–73Derived
OLMo 2 7B Instruct7BQ8_010.3 GB+9.7 GB57–75Derived
OLMo 3 7B Instruct7BQ8_010.3 GB+9.7 GB57–75Derived
WizardLM-2 7B7BQ4_K_M5.14 GB+14.9 GB100–133Derived
Mistral 7B Instruct v0.37BQ6_K6.75 GB+13.3 GB74–98Derived
Zephyr 7B Beta7BQ6_K6.75 GB+13.3 GB74–98Derived
Gemma 4 E2B ITE2BQ8_05.2 GB+14.8 GB≤171Ceiling
Qwen3.5 4B4BQ8_04.97 GB+15 GB≤182Ceiling
Gemma 3 4B IT4BQ8_05.05 GB+15 GB≤184Ceiling

≤3B · 14

Radeon RX 7900 XT — what LLMs can it run? — ≤3B
ModelQuantEst. VRAMHeadroomtok/s
Qwen3 4B Instruct4BQ6_K4.05 GB+16 GB≤256Ceiling
Phi-4 Mini Instruct3.8BQ8_04.81 GB+15.2 GB≤206Ceiling
Phi-3.5 Mini Instruct3.8BQ8_05.89 GB+14.1 GB≤207Ceiling
Granite 4.2 3B3BQ8_04.41 GB+15.6 GB≤217Ceiling
Llama 3.2 3B Instruct3BQ8_04.05 GB+16 GB≤247Ceiling
Qwen2.5 3B Instruct3BQ8_03.59 GB+16.4 GB≤256Ceiling
SmolLM3 3B3BQ8_03.73 GB+16.3 GB≤257Ceiling
Gemma 2 2B Instruct2BQ8_03.34 GB+16.7 GB≤304Ceiling
Qwen3.5 2B2BQ8_02.23 GB+17.8 GB≤404Ceiling
Qwen3 1.7B Instruct1.7BQ8_02.39 GB+17.6 GB≤460Ceiling
Qwen2.5 1.5B Instruct1.5BQ8_01.83 GB+18.2 GB≤516Ceiling
Llama 3.2 1B Instruct1BQ8_01.51 GB+18.5 GB≤640Ceiling
Qwen3.5 0.8B0.8BQ8_00.94 GB+19.1 GB≤988Ceiling
Qwen2.5 0.5B Instruct0.5BQ8_00.6 GB+19.4 GB≤1633Ceiling

How this list is built

Each row is the lowest-perplexity-loss quant of that model whose estimated total — weights plus KV cache at 4K context plus activation buffer — uses at most 88% of the card. That is the calculator's "green" threshold, so every row here has real headroom rather than only just fitting. Raise the context length and the list shortens; the calculator lets you check any combination directly. The speed column is this card: a measured run, a range scaled from this card's own Llama 2 7B benchmark, or a bandwidth ceiling. A figure that only exists for the RTX 4090 is labelled as that card.

A further 10 models load but with no headroom to spare (up to 105% of VRAM) — the Quant Hub’s GPU chips count those too, which is why its number is higher.

Measured on this card

No benchmark runs in this index were recorded on a Radeon RX 7900 XT. Every figure on this page is calculated from the model architecture and the quant level — treat them as estimates, not measurements.

Setup guides for this card

Step-by-step guides written for the Radeon RX 7900 XT's runtime or memory size, with the commands and the checks that prove the model is running on the card.

Stepping up

A Radeon RX 7900 XTX (24GB) fits 11 more of the indexed models than this card. Radeon RX 7900 XTX →

Before buying, hear the speed difference on a model both cards hold: Radeon RX 7900 XT vs Radeon RX 7900 XTX (Qwen2.5 32B Instruct) →

Common questions

What is the best local LLM for a Radeon RX 7900 XT?

For everyday use, DeepSeek-V2-Lite Chat at Q4_K_M — about 10.1 GB of the card's 20 GB at 4K context, leaving 9.9 GB for a longer window. If you want the largest thing that will load, that is Qwen2.5 32B Instruct at Q3_K_M (17.5 GB, 2.5 GB spare). "Best" here means best fit for the memory budget — this index does not run task benchmarks, so it cannot tell you which model is smarter.

Can a Radeon RX 7900 XT run Qwen3 32B Instruct?

Only just. Its smallest build here, Q3_K_M, needs about 17.7 GB against 20.0 GB usable — that loads with nothing else running, with no margin for a longer context window. It is not on the list above, which requires a model to stay inside 88% of usable capacity.

How many tokens per second does a Radeon RX 7900 XT do on an 8B model at Q4?

This index has no measured run on this card, so it does not publish a figure. What can be stated from specifications: generating a token requires reading every weight once, Llama 3.1 8B Instruct at Q4_K_M is 4.6 GB of weights, and this card moves 800 GB/s — a ceiling near 173 tok/s. Batch size, context length, the runtime and how much of the model sits in cache all take you below it.

Radeon RX 7900 XT or Radeon RX 9070 XT for local LLMs?

They do not hold the same set: Radeon RX 7900 XT fits 73 and Radeon RX 9070 XT 63 of 110 at 4K. Speed is the other difference — 800 GB/s against 640 GB/s, a 1.3× gap in how fast the weights can be read, which is what token generation is bound by. The Radeon RX 7900 XT generates faster on any model both can hold.

73 of 110 indexed models fit comfortably in 20GB at 4K context, each at the highest-quality quant that still leaves headroom.

This page's figures change when the model or the runtime does.Last updated 2026-10-18 RSS → /feed.xml