NVIDIA · workstation

RTX 4000 SFF Ada Generation

RTX 4000 SFF Ada Generation has 20 GB of VRAM at 280 GB/s — about 18.60 GiB usable after driver and compositor overhead. 1796 of 2118 indexed models fit at 64K context with q8_0 KV.

Spec sheet· bandwidth, theoreticalFrom the file· fit from summed bytesPredicted· speed
Memory
20 GB
GDDR6
Bandwidth
280 GB/s
160-bit bus
Tensor FP16
77 TF
dense
TDP
70 W
$1250 MSRP
KV cachef16q8_0q4_0quantizing the KV cache is a ~2× lever on the dominant term at long context
vision language 170text 1522image 2video 16audio asr 39embedding 26audio tts 21

What fits at 64K context

largest quantization that fits, per model · 1796 of 2118 indexed
ModelBest quantParamsWeightsKVTotal in memoryHeadroomtok/s
Qwen3.6-27B-uncensored-heretic-v2Q4_K_M27.4B15.41 GiB2.13 GiB18.60 GiB0.00 GiB9±22%
Qwen3.6-27B-Heretic2-ThinkingI1-Q4_K_M27.4B15.41 GiB2.13 GiB18.60 GiB0.00 GiB9±22%
Qwen3.6-27B-Uncensored-AggressiveI1-Q4_K_M27.4B15.41 GiB2.13 GiB18.60 GiB0.00 GiB9±22%
Qwen-3.5-Opus-GLM-27BI1-Q4_K_M26.9B15.41 GiB2.13 GiB18.60 GiB0.00 GiB9±22%
Qwen3.6-27B-abliteratedI1-Q4_K_M27.4B15.41 GiB2.13 GiB18.60 GiB0.00 GiB9±22%
KoQweopus-3.5-27B-experimentalI1-Q4_K_M27.8B15.41 GiB2.13 GiB18.60 GiB0.00 GiB9±22%
Webcoda-AI-27BI1-Q4_K_M27.4B15.41 GiB2.13 GiB18.60 GiB0.00 GiB9±22%
Qwen3.5-27B-imabari-v2I1-Q4_K_M27.8B15.41 GiB2.13 GiB18.60 GiB0.00 GiB9±22%
Qwen3.5-27B-uncensored-heretic-v1I1-Q4_K_M27.4B15.41 GiB2.13 GiB18.60 GiB0.00 GiB9±22%
Carnice-V2-27bI1-Q4_K_M27.4B15.41 GiB2.13 GiB18.60 GiB0.00 GiB9±22%
Qwen3.5-Queen-27BI1-Q4_K_M27.4B15.41 GiB2.13 GiB18.60 GiB0.00 GiB9±22%
GRaPE-2-ProI1-Q4_K_M27.8B15.41 GiB2.13 GiB18.60 GiB0.00 GiB9±22%
Huihui-Qwen3.6-27B-abliteratedQ4_K_M27.8B15.41 GiB2.13 GiB18.60 GiB0.00 GiB9±22%
Qwen3.5-27B-abliteratedQ4_K_M26.9B15.41 GiB2.13 GiB18.60 GiB0.00 GiB9±22%
ThinkingCap-Qwen3.6-27B-hereticQ4_K_M27.4B15.41 GiB2.13 GiB18.60 GiB0.00 GiB9±22%
MusaCoder-27BQ4_K_M15.41 GiB2.13 GiB18.60 GiB0.00 GiB9±22%
Qwen-Image-BenchQ4_K_M27.4B15.41 GiB2.13 GiB18.60 GiB0.00 GiB9±22%
Bonsai-27B-unpackedQ4_K_M27.4B15.41 GiB2.13 GiB18.60 GiB0.00 GiB9±22%
Ternary-Bonsai-27B-unpackedQ4_K_M27.4B15.41 GiB2.13 GiB18.60 GiB0.00 GiB9±22%
Qwen3.6-27B-Claude-Opus-Reasoning-Distill-v2-hereticQ4_K_M27.4B15.41 GiB2.13 GiB18.60 GiB0.00 GiB9±22%
Darwin-28B-REASONI1-Q4_K_M26.9B15.41 GiB2.13 GiB18.60 GiB0.00 GiB9±22%
Huihui-Qwen3.5-27B-Claude-4.6-Opus-abliteratedI1-Q4_K_M27.8B15.41 GiB2.13 GiB18.60 GiB0.00 GiB9±22%
Qwen3.5-27BQ4_K_M27.8B15.41 GiB2.13 GiB18.60 GiB0.00 GiB9±22%
Qwen3.5-27B-WebNovel-Writer-zhI1-Q4_K_M26.9B15.41 GiB2.13 GiB18.60 GiB0.00 GiB9±22%
Qwen3.5-27B_Homebrew-v2I1-Q4_K_M27.4B15.41 GiB2.13 GiB18.60 GiB0.00 GiB9±22%
Qwen3.5-27B-Claude-4.6-Opus-Reasoning-DistilledQ4_K_M27.8B15.41 GiB2.13 GiB18.60 GiB0.00 GiB9±22%
internlm2-math-plus-20bI1-Q4_K_M19.9B11.16 GiB6.38 GiB18.60 GiB0.00 GiB9±22%
Rocinante-XL-16B-v1I1-Q5_K_S16.1B10.38 GiB7.17 GiB18.60 GiB0.00 GiB9±22%
Qwen3.5-27B-Engineer-Deckard-GeminiI1-Q4_K_M27.7B15.40 GiB2.13 GiB18.59 GiB0.01 GiB9±22%
Qwen3.5-27B-HERETIC-Polaris-Advanced-Thinking-Alpha-uncensoredI1-Q4_K_M27.4B15.40 GiB2.13 GiB18.59 GiB0.01 GiB9±22%
Qwen3.5-27B-Deckard-PKD-Heretic-Uncensored-ThinkingI1-Q4_K_M27.4B15.40 GiB2.13 GiB18.59 GiB0.01 GiB9±22%
Huihui-Qwen3.5-27B-abliteratedI1-Q4_K_M27.8B15.40 GiB2.13 GiB18.59 GiB0.01 GiB9±22%
Qwen3.5-27B-Unredacted-MAXI1-Q4_K_M27.4B15.40 GiB2.13 GiB18.59 GiB0.01 GiB9±22%
Qwen3.5-27B-hereticI1-Q4_K_M27.4B15.40 GiB2.13 GiB18.59 GiB0.01 GiB9±22%
Qwen3.5-27B-DerestrictedI1-Q4_K_M27.8B15.40 GiB2.13 GiB18.59 GiB0.01 GiB9±22%
Pantheon-Reasoning-27BIQ4_NL27.8B15.40 GiB2.13 GiB18.59 GiB0.01 GiB9±22%
Qwen3.5-27BIQ4_NL27.8B15.40 GiB2.13 GiB18.59 GiB0.01 GiB9±22%
EuroLLM-22B-Instruct-2512Q3_K_M22.6B10.35 GiB7.17 GiB18.59 GiB0.01 GiB9±22%
Qwen3.5-40B-Claude-4.6-Opus-Deckard-Heretic-Uncensored-ThinkingI1-IQ3_XXS39.5B14.33 GiB3.19 GiB18.58 GiB0.02 GiB9±22%
Janus-Pro-7BI1-IQ1_S7.4B1.61 GiB15.94 GiB18.58 GiB0.02 GiB9±22%
deepseek-coder-7b-instruct-v1.5I1-IQ1_S6.9B1.61 GiB15.94 GiB18.58 GiB0.02 GiB9±22%
Qwen3.6-27B-A3B-CoderMoEI1-Q5_K_S26.7B16.91 GiB0.66 GiB18.58 GiB0.02 GiB35±37%
Nemotron-3-Nano-Omni-30B-A3B-Reasoning-BF16UD-IQ3_S33.0B17.53 GiB0.00 GiB18.57 GiB0.03 GiB9±22%
Qwen3.5-21B-Claude-4.6-Opus-Deckard-Heretic-Uncensored-ThinkingI1-Q6_K21.3B15.91 GiB1.59 GiB18.57 GiB0.03 GiB9±22%
Qwen3.6-21B-IQ-Ultra-Heretic-Uncensored-ThinkingI1-Q6_K21.3B15.91 GiB1.59 GiB18.57 GiB0.03 GiB9±22%
gemma-4-E2B-it-Uncensored-MAXF325.1B17.33 GiB0.25 GiB18.57 GiB0.03 GiB9±22%
gemma-7bI1-IQ2_XS8.5B2.62 GiB14.88 GiB18.57 GiB0.03 GiB9±22%
Skywork-R1V3-38BQ4_K_S38.4B17.49 GiB0.00 GiB18.56 GiB0.04 GiB9±22%
reka-flash-3.1Q4_K_L20.9B13.10 GiB4.38 GiB18.56 GiB0.04 GiB9±22%
reka-flash-3Q4_K_L20.9B13.10 GiB4.38 GiB18.56 GiB0.04 GiB9±22%
medgemma-27b-itIQ4_NL28.8B14.50 GiB2.98 GiB18.56 GiB0.04 GiB9±22%
gemma-3-27b-it-abliteratedIQ4_NL27.4B14.50 GiB2.98 GiB18.56 GiB0.04 GiB9±22%
gemma-3-27b-itIQ4_NL27.4B14.50 GiB2.98 GiB18.56 GiB0.04 GiB9±22%
medgemma-27b-text-itIQ4_NL27.0B14.50 GiB2.98 GiB18.56 GiB0.04 GiB9±22%
GLM-4.7-Flash-Claude-Opus-4.5-High-Reasoning-DistillMoEIQ4_NL31.2B15.79 GiB1.76 GiB18.56 GiB0.04 GiB25±37%
Huihui-Qwen3-Coder-Next-abliteratedMoEI1-IQ1_M79.7B16.76 GiB0.80 GiB18.55 GiB0.05 GiB43±37%
Gemma-4-31B-Isometry-RPI1-Q2_K32.7B11.53 GiB5.94 GiB18.54 GiB0.06 GiB9±22%
Gemma-4-Dark-Gemistry-31BI1-Q2_K32.7B11.53 GiB5.94 GiB18.54 GiB0.06 GiB9±22%
Prosopon-31BI1-Q2_K32.7B11.53 GiB5.94 GiB18.54 GiB0.06 GiB9±22%
Gemma-4-Novelist-Eclipse-31BI1-Q2_K32.7B11.53 GiB5.94 GiB18.54 GiB0.06 GiB9±22%
From the filePredictedwhat 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.

Measured on this card

third-party benchmarks, aggregated
WorkloadMedianMiddle 50%Runs
Image generation10.30 it/s7.6410.699
Benchmarked· n=9

Aggregated from community-submitted runs, so the spread is wide by nature — it covers different models, resolutions, step counts and settings, not one controlled configuration. Read the middle 50% rather than the median alone. These figures are reproduced with attribution from vladmandic-sd-data-benchmark, which publishes no licence — so we display and link rather than redistribute them.

Questions people ask

What AI models can a RTX 4000 SFF Ada Generation run?
1796 of 2118 indexed open-weight models fit a RTX 4000 SFF Ada Generation at 65,536 context with q8_0 KV cache, the largest being Qwen3.6-27B-uncensored-heretic-v2 at Q4_K_M. That covers text, vision-language, image, video and speech models.
How much usable memory does a RTX 4000 SFF Ada Generation actually have?
Its nameplate is 20 GB, but about 18.60 GiB is available to a model once driver and compositor overhead is accounted for.
Is a RTX 4000 SFF Ada Generation fast for local AI?
Its memory bandwidth is 280 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.