AMD · consumer

Radeon RX 6400

Radeon RX 6400 has 4 GB of VRAM at 128 GB/s — about 3.72 GiB usable after driver and compositor overhead. 349 of 2118 indexed models fit at 32K context with f16 KV.

Spec sheet· bandwidth, theoreticalFrom the file· fit from summed bytesPredicted· speed
Memory
4 GB
GDDR6
Bandwidth
128 GB/s
64-bit bus
Tensor FP16
—
dense
TDP
53 W
$159 MSRP
Context4K8K16K32K64K128K
KV cachef16q8_0q4_0quantizing the KV cache is a ~2× lever on the dominant term at long context
text 256vision language 32audio tts 17embedding 13video 2audio asr 29

What fits at 32K context

largest quantization that fits, per model · 349 of 2118 indexed
ModelBest quantParamsWeights●KV●Total in memory◐Headroom◐tok/s◐
Qwen2.5-3B-Instruct-abliteratedI1-IQ1_M3.1B1.68 GiB1.13 GiB3.72 GiB0.00 GiB28±26.5%
Surogate-3.5-2BQ8_02.8B2.44 GiB0.38 GiB3.71 GiB0.01 GiB28±26.5%
DeepSeek-OCRMoEQ5_03.3B1.88 GiB0.94 GiB3.71 GiB0.01 GiB37±37%
Holo-3.1-4BI1-IQ2_S5.2B1.79 GiB1.00 GiB3.71 GiB0.01 GiB29±26.5%
AfriqueQwen3.5-4BI1-IQ2_S5.2B1.79 GiB1.00 GiB3.71 GiB0.01 GiB29±26.5%
TimeOmni-1-4BI1-IQ2_S5.2B1.79 GiB1.00 GiB3.71 GiB0.01 GiB29±26.5%
Hunyuan-1.8B-InstructQ3_K_S1.8B0.81 GiB2.00 GiB3.70 GiB0.02 GiB28±26.5%
dolphin-2_6-phi-2Q8_02.8B2.75 GiB0.00 GiB3.70 GiB0.02 GiB29±26.5%
G9v3-3BQ2_K3.0B1.18 GiB1.63 GiB3.70 GiB0.02 GiB28±26.5%
Vikhr-Gemma-2B-instructIQ2_XS2.6B0.93 GiB1.85 GiB3.70 GiB0.02 GiB29±26.5%
Gemmasutra-Mini-2B-v1I1-IQ2_XS2.6B0.93 GiB1.85 GiB3.70 GiB0.02 GiB29±26.5%
gemma-2-2b-itIQ2_XS2.6B0.93 GiB1.85 GiB3.70 GiB0.02 GiB29±26.5%
granite-4.0-7B-A1B-Creative-v0.1MoEI1-IQ3_XS6.7B2.58 GiB0.25 GiB3.70 GiB0.02 GiB67±37%
Qwen3.5-4B-NSFW-ARA-Heretic-LiteroticaI1-Q2_K4.2B1.78 GiB1.00 GiB3.70 GiB0.02 GiB29±26.5%
Qwen3.5-4B-RpRMax-v1I1-Q2_K4.7B1.78 GiB1.00 GiB3.70 GiB0.02 GiB29±26.5%
Holo-3.1-4B-uncensored-hereticI1-Q2_K4.5B1.78 GiB1.00 GiB3.70 GiB0.02 GiB29±26.5%
GRaPE-2-MiniI1-Q2_K4.7B1.78 GiB1.00 GiB3.70 GiB0.02 GiB29±26.5%
Qwen3.5-DPO-4B-2I1-Q2_K4.2B1.78 GiB1.00 GiB3.70 GiB0.02 GiB29±26.5%
Qwen3.5-4B-BaseQ2_K4.7B1.78 GiB1.00 GiB3.70 GiB0.02 GiB29±26.5%
NuExtract3Q2_K4.5B1.78 GiB1.00 GiB3.70 GiB0.02 GiB29±26.5%
Huihui-Qwen3.5-4B-Claude-4.6-Opus-abliteratedI1-Q2_K4.7B1.78 GiB1.00 GiB3.70 GiB0.02 GiB29±26.5%
Qwopus3.5-4B-v3-hereticI1-Q2_K4.5B1.78 GiB1.00 GiB3.70 GiB0.02 GiB29±26.5%
Aureth-4B-Qwen3.5I1-Q2_K4.5B1.78 GiB1.00 GiB3.70 GiB0.02 GiB29±26.5%
deepseek-coder-5.7bmqa-baseQ2_K5.7B2.27 GiB0.50 GiB3.69 GiB0.03 GiB29±26.5%
LFM2.5-Queen-Opus-4.7-8B-A1BMoEI1-IQ2_S8.5B2.41 GiB0.38 GiB3.69 GiB0.03 GiB54±37%
LFM2.5-8B-A1B-KO-SFTMoEI1-IQ2_S8.5B2.41 GiB0.38 GiB3.69 GiB0.03 GiB54±37%
LFM2.5-8B-A1B-hereticMoEI1-IQ2_S8.5B2.41 GiB0.38 GiB3.69 GiB0.03 GiB54±37%
LFM2.5-8B-A1B-SOMPOA-heresyMoEI1-IQ2_S8.5B2.41 GiB0.38 GiB3.69 GiB0.03 GiB54±37%
Huihui-LFM2.5-8B-A1B-abliteratedMoEI1-IQ2_S8.5B2.41 GiB0.38 GiB3.69 GiB0.03 GiB54±37%
Supertron2.1-8B-A1BMoEI1-IQ2_S8.5B2.41 GiB0.38 GiB3.69 GiB0.03 GiB54±37%
granite-3.1-1b-a400m-instructMoEQ8_01.3B1.32 GiB1.50 GiB3.69 GiB0.03 GiB24±37%
alduin-4b-it-baseI1-Q3_K_M4.3B1.96 GiB0.79 GiB3.67 GiB0.05 GiB29±26.5%
GRM-Kerlin-3b-AbliteratedIQ4_XS3.1B1.63 GiB1.13 GiB3.67 GiB0.05 GiB29±26.5%
MATE-3BIQ4_XS3.1B1.63 GiB1.13 GiB3.67 GiB0.05 GiB29±26.5%
Mythos-nano-OBLITERATEDIQ4_XS3.1B1.63 GiB1.13 GiB3.67 GiB0.05 GiB29±26.5%
Qwen2.5-3B-Instruct-UncensoredIQ4_XS3.1B1.63 GiB1.13 GiB3.67 GiB0.05 GiB29±26.5%
VibeThinker-3B-OBLITERATEDIQ4_XS3.1B1.63 GiB1.13 GiB3.67 GiB0.05 GiB29±26.5%
Nanonets-OCR-sIQ4_XS3.8B1.63 GiB1.13 GiB3.67 GiB0.05 GiB29±26.5%
LFM2.5-8B-A1BMoEUD-IQ1_M8.5B2.40 GiB0.38 GiB3.67 GiB0.05 GiB55±37%
EXAONE-4.0-1.2B-abliteratedI1-Q4_11.5B0.91 GiB1.88 GiB3.67 GiB0.05 GiB29±26.5%
gemma-3-4b-it-roleplay-tuned-v1I1-Q3_K_M4.3B1.95 GiB0.79 GiB3.67 GiB0.05 GiB29±26.5%
Gemma-3-4B-VL-it-Gemini-Pro-Heretic-Uncensored-ThinkingQ3_K_M4.3B1.95 GiB0.79 GiB3.67 GiB0.05 GiB29±26.5%
gemma-3-4b-it-roleplay-tuned-v2I1-Q3_K_M4.3B1.95 GiB0.79 GiB3.67 GiB0.05 GiB29±26.5%
medgemma-1.5-4b-itQ3_K_M4.3B1.95 GiB0.79 GiB3.67 GiB0.05 GiB29±26.5%
gemma-3-4b-it-heretic-uncensored-abliterated-ExtremeI1-Q3_K_M4.3B1.95 GiB0.79 GiB3.67 GiB0.05 GiB29±26.5%
medgemma-4b-itQ3_K_M4.3B1.95 GiB0.79 GiB3.67 GiB0.05 GiB29±26.5%
gemma-3-4b-it-abliteratedQ3_K_M4.3B1.95 GiB0.79 GiB3.67 GiB0.05 GiB29±26.5%
amoral-gemma3-4B-v1Q3_K_M4.3B1.95 GiB0.79 GiB3.67 GiB0.05 GiB29±26.5%
Gemma3-4B-CodeCenturionI1-Q3_K_M4.3B1.95 GiB0.79 GiB3.67 GiB0.05 GiB29±26.5%
ArrowMint-Gemma3-4B-YUKI-v0.1I1-Q3_K_M4.3B1.95 GiB0.79 GiB3.67 GiB0.05 GiB29±26.5%
gemma-3-4b-itQ3_K_M4.3B1.95 GiB0.79 GiB3.67 GiB0.05 GiB29±26.5%
Qwen3.5-2B-hereticQ8_02.2B2.39 GiB0.38 GiB3.66 GiB0.06 GiB29±26.5%
Dolphin3.0-Qwen2.5-3bIQ4_XS3.1B1.62 GiB1.13 GiB3.66 GiB0.06 GiB29±26.5%
Qwen2.5-Coder-3B-Instruct-abliteratedI1-IQ4_XS3.1B1.62 GiB1.13 GiB3.66 GiB0.06 GiB29±26.5%
Qwen2.5-Coder-3B-InstructIQ4_XS3.1B1.62 GiB1.13 GiB3.66 GiB0.06 GiB29±26.5%
Mythos-nanoI1-IQ4_XS3.1B1.62 GiB1.13 GiB3.66 GiB0.06 GiB29±26.5%
Qwen2.5-3B-InstructIQ4_XS3.1B1.62 GiB1.13 GiB3.66 GiB0.06 GiB29±26.5%
Qwen2.5-3BIQ4_XS3.1B1.62 GiB1.13 GiB3.66 GiB0.06 GiB29±26.5%
Qwen2.5-Coder-3BIQ4_XS3.1B1.62 GiB1.13 GiB3.66 GiB0.06 GiB29±26.5%
raspberry-3BIQ4_XS3.1B1.62 GiB1.13 GiB3.66 GiB0.06 GiB29±26.5%
●From the file◐Predictedwhat these mean

Speed is modeled, not measured: decode is memory-bandwidth bound, so tokens per second is bytes read per token against achievable bandwidth. Mixture-of-experts models carry a wider band because only the routed experts are read each step, and few have been measured publicly.

Questions people ask

What AI models can a Radeon RX 6400 run?
349 of 2118 indexed open-weight models fit a Radeon RX 6400 at 32,768 context with f16 KV cache, the largest being Qwen2.5-3B-Instruct-abliterated at I1-IQ1_M. That covers text, vision-language, image, video and speech models.
How much usable memory does a Radeon RX 6400 actually have?
Its nameplate is 4 GB, but about 3.72 GiB is available to a model once driver and compositor overhead is accounted for.
Is a Radeon RX 6400 fast for local AI?
Its memory bandwidth is 128 GB/s, and that figure — not teraflops — is what governs token generation speed. Capacity decides what you can run; bandwidth decides how fast it runs.