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LTX-2

Lightricks/LTX-2

LTX-2 at Q4_K_M is exactly 12,840,118,752 bytes (11.96 GiB / 12.84 GB) — an effective 5.442 bits per weight, not the nominal 4.

From the file· summed from 1 file(s)
Parameters
18.9B
Architecture
ltxv
Context
native (config.json)
License

Shipped quantizations

exact bytes, summed from published files
QuantSizeExact bytesEffective bpwTensorsPublisher
Q2_K7.48 GiB8,026,456,9603.402QuantStack
Q2_K7.54 GiB8,097,016,2883.432unsloth
Q3_K_S8.82 GiB9,474,222,5604.015unsloth
Q3_K_S8.92 GiB9,574,482,8164.058QuantStack
UD-Q2_K_L9.39 GiB10,077,415,9044.271unsloth
UD-Q3_K_M9.39 GiB10,077,415,9044.271unsloth
Q3_K_M9.42 GiB10,117,491,1684.2883510unsloth
Q3_K_M9.61 GiB10,317,595,5204.373QuantStack
Q3_K_L9.98 GiB10,718,849,5044.543unsloth
Q4_010.57 GiB11,347,864,0324.8093510unsloth
UD-Q4_K_S10.83 GiB11,630,029,2804.929unsloth
Q4_K_S11.04 GiB11,855,505,8885.024unsloth
Q4_111.46 GiB12,304,165,3445.215unsloth
Q4_K_S11.47 GiB12,317,819,7765.221QuantStack
Q4_K_M11.96 GiB12,840,118,7525.4423510unsloth
Q4_K_M12.46 GiB13,374,456,7045.668QuantStack
Q5_K_S12.69 GiB13,622,356,4485.773unsloth
Q5_012.72 GiB13,663,119,8405.791unsloth
Q5_K_S13.18 GiB14,150,730,6245.997QuantStack
Q5_K_M13.35 GiB14,335,388,1286.0753510unsloth
Q5_113.62 GiB14,619,421,1526.196unsloth
Q5_K_M13.97 GiB14,996,341,6326.356QuantStack
Q6_K14.87 GiB15,966,448,0966.7673510unsloth
Q6_K15.47 GiB16,610,689,9207.040QuantStack
Q8_019.01 GiB20,407,560,6728.6493510unsloth
Q8_019.65 GiB21,096,498,0488.941QuantStack
BF1635.18 GiB37,771,979,23216.008unsloth
F1635.18 GiB37,771,979,23216.0083510unsloth

Pipeline components

a diffusion model is a graph of parts, not one file
ComponentSizeShareCan live on the CPU?
vae2.28 GiB1%no, must be resident
denoiser158.00 GiB62%no, must be resident
text encoder93.47 GiB37%yes — the usual first VRAM saving
Full pipeline253.74 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 9.89 GiB. The real file is 11.96 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 LTX-2 need?
Q4_K_M is exactly 12,840,118,752 bytes (11.96 GiB) in weights. Add the KV cache, which depends on your context length, plus roughly half a gigabyte of runtime overhead.
Which quantization of LTX-2 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.