black-forest-labs · image

FLUX.1-schnell

black-forest-labs/FLUX.1-schnell

FLUX.1-schnell at Q4_K_M is exactly 6,911,345,696 bytes (6.44 GiB / 6.91 GB) — an effective 4.650 bits per weight, not the nominal 4.

From the file· summed from 1 file(s)
Parameters
11.9B
Architecture
flux
Context
native (config.json)
License
apache-2.0

Shipped quantizations

exact bytes, summed from published files
QuantSizeExact bytesEffective bpwTensorsPublisher
Q2_K3.73 GiB4,003,218,4642.693unsloth
Q2_K3.73 GiB4,010,296,3522.698lllyasviel
Q2_K3.73 GiB4,010,296,3522.698city96
Q3_K_S4.85 GiB5,205,132,3203.502unsloth
Q3_K_S4.85 GiB5,212,210,2083.507city96
Q3_K_S4.85 GiB5,212,210,2083.507lllyasviel
Q3_K_M4.98 GiB5,348,017,1843.598776unsloth
Q4_06.31 GiB6,770,707,3604.555lllyasviel
Q4_06.31 GiB6,770,707,3604.555city96
Q4_K_S6.31 GiB6,776,865,8244.559unsloth
Q4_06.31 GiB6,776,865,8244.559776unsloth
Q4_K_S6.32 GiB6,783,943,7124.564lllyasviel
Q4_K_S6.32 GiB6,783,943,7124.564city96
Q4_K_M6.44 GiB6,911,345,6964.650776unsloth
Q4_16.99 GiB7,510,346,6565.053city96
Q4_16.99 GiB7,510,346,6565.053lllyasviel
Q4_17.00 GiB7,516,505,1205.057unsloth
Q5_07.68 GiB8,249,985,9525.550lllyasviel
Q5_07.68 GiB8,249,985,9525.550city96
Q5_07.69 GiB8,256,144,4165.554unsloth
Q5_K_S7.69 GiB8,256,144,4165.554unsloth
Q5_K_S7.70 GiB8,263,222,3045.559city96
Q5_K_S7.70 GiB8,263,222,3045.559lllyasviel
Q5_K_M7.82 GiB8,399,029,2805.651776unsloth
Q5_18.37 GiB8,989,625,2486.048lllyasviel
Q5_18.37 GiB8,989,625,2486.048city96
Q5_18.38 GiB8,995,783,7126.052unsloth
Q6_K9.15 GiB9,827,877,9206.612776unsloth
Q6_K9.16 GiB9,834,955,8086.617city96
Q6_K9.16 GiB9,834,955,8086.617lllyasviel
Q8_011.82 GiB12,687,821,7288.536lllyasviel
Q8_011.82 GiB12,687,821,7288.536city96
Q8_011.82 GiB12,693,980,1928.540776unsloth
F1622.15 GiB23,782,411,16816.000city96
F1622.15 GiB23,782,411,16816.000lllyasviel
BF1622.15 GiB23,788,569,63216.004unsloth
F1622.15 GiB23,788,569,63216.004776unsloth

Pipeline components

a diffusion model is a graph of parts, not one file
ComponentSizeShareCan live on the CPU?
text encoder 28.87 GiB28%yes — the usual first VRAM saving
text encoder0.23 GiB1%yes — the usual first VRAM saving
denoiser22.46 GiB71%no, must be resident
vae0.16 GiB0%no, must be resident
Full pipeline31.72 GiBresident if nothing is offloaded

The parameter count published for a diffusion model describes the denoiser alone. Running it also requires its text encoder and VAE, and the text encoder is often nearly as large as the denoiser — which is why offloading it is the standard first move when you run out of memory. This repository also ships a single-file copy of the denoiser at its root; we count it once, not twice.

We publish component sizes here, not throughput. Community-submitted image-generation rates do exist for many GPUs and we show them on the hardware pages, but they aggregate runs at different resolutions, step counts and settings, so they cannot be attributed to one model. Peak memory during sampling is unmeasured by any public source, and we do not estimate it.

Compare with

same modality, comparable size

Will it run on your card?

full quant x context sweep

Why other calculators give a different number

A parameters × bits ÷ 8 estimate puts Q4_K_M at roughly 6.23 GiB. The real file is 6.44 GiB, because a quantization is a mixture and some tensors are always kept at higher precision.

Architecture

Architecture unavailable — this repository is gated and no ungated mirror was found. Exact file sizes above are still authoritative; only the KV math needs the config.

Questions people ask

How much VRAM does FLUX.1-schnell need?
Q4_K_M is exactly 6,911,345,696 bytes (6.44 GiB) in weights. Add the KV cache, which depends on your context length, plus roughly half a gigabyte of runtime overhead.
Which quantization of FLUX.1-schnell should I use?
Q4_K_M is the usual default. Pick the largest quantization that fits your card at the context you actually need — the table above gives exact sizes for every one published.