SignRoundV2: Toward Closing the Performance Gap in Extremely Low-Bit Post-Training Quantization for LLMs

In three linesSignRoundV2 is a post-training quantization framework for LLMs maintaining performance under extreme compression (2-4 bits). It combines adaptive mixed-precision strategy guided by gradients and lightweight stabilization techniques. Results show ~1% performance gap at 4.5 bits average in mixed MXFP, with substantial improvements in challenging 2-bit weight-only quantization.

Summary generated by Claude — human-verified