  The recent rise of large language models (LLMs) has resulted in increased
efforts towards running LLMs at reduced precision. Running LLMs at lower
precision supports resource constraints and furthers their democratization,
enabling users to run billion-parameter LLMs on their personal devices. To
supplement this ongoing effort, we propose INT-FP-QSim: an open-source
simulator that enables flexible evaluation of LLMs and vision transformers at
various numerical precisions and formats. INT-FP-QSim leverages existing
open-source repositories such as TensorRT, QPytorch and AIMET for a combined
simulator that supports various floating point and integer formats. With the
help of our simulator, we survey the impact of different numerical formats on
the performance of LLMs and vision transformers at 4-bit weights and 4-bit or
8-bit activations. We also compare recently proposed methods like Adaptive
Block Floating Point, SmoothQuant, GPTQ and RPTQ on the model performances. We
hope INT-FP-QSim will enable researchers to flexibly simulate models at various
precisions to support further research in quantization of LLMs and vision
transformers.
