Preprint Open access
Deflating the Hessian: Rank-4 W4A4 Quantization for Multimodal Diffusion Transformers
In diffusion transformers, low-rank branches can mitigate 4-bit weight--activation (W4A4) post-training quantization (PTQ) loss by decomposing each weight into a low-bit residual and a high-precision low-rank component. Existing low-rank PTQ approaches, however, either optimize low-rank compensation and residual quanti …