  As part of the Snowmass'21 planning exercise, the Advanced Accelerator
Concepts community proposed developing multi-TeV linear colliders and
considered beam-beam effects for these machines. Such colliders operate under a
high disruption regime with an enormous number of electron-positron pairs
produced from QED effects. Thus, it requires a self-consistent treatment of the
fields produced by the pairs, which is not implemented in state-of-the-art
beam-beam codes such as GUINEA-PIG. WarpX is a parallel, open-source, and
portable particle-in-cell code with an active developer community that models
QED processes with photon and pair generation in relativistic laser-beam
interactions. However, its application to beam-beam collisions has yet to be
fully explored. In this work, we benchmark the luminosity spectra, photon
spectra, and coherent production process from WarpX against GUINEA-PIG in the
ILC and ultra-tight collision scenarios. Our performance comparison
demonstrates a significant speed-up advantage of WarpX, ensuring a more robust
and efficient modeling of electron-positron collisions at multi-TeV energies.
