Scaling Laws for Native Multimodal Models Scaling Laws for Native
  Multimodal Models
Authors: name: Mustafa Shukor; name: Enrico Fini; name: Victor Guilherme Turrisi da Costa; name: Matthieu Cord; name: Joshua Susskind; name: Alaaeldin El-Nouby
Published: 2025-04-10 17:57:28

Abstract: Building general-purpose models that can effectively perceive the world
through multimodal signals has been a long-standing goal. Current approaches
involve integrating separately pre-trained components, such as connecting
vision encoders to LLMs and continuing multimodal training. While such
approaches exhibit remarkable sample efficiency, it remains an open question
whether such late-fusion architectures are inherently superior. In this work,
we revisit the architectural design of native multimodal models (NMMs)--those
trained from the ground up on all modalities--and conduct an extensive scaling
laws study, spanning 457 trained models with different architectures and
training mixtures. Our investigation reveals no inherent advantage to
late-fusion architectures over early-fusion ones, which do not rely on image
encoders. On the contrary, early-fusion exhibits stronger performance at lower
parameter counts, is more efficient to train, and is easier to deploy.
Motivated by the strong performance of the early-fusion architectures, we show
that incorporating Mixture of Experts (MoEs) allows for models that learn
modality-specific weights, significantly enhancing performance.