  Deep learning (DL) is characterised by its dynamic nature, with new deep
neural network (DNN) architectures and approaches emerging every few years,
driving the field's advancement. At the same time, the ever-increasing use of
mobile devices (MDs) has resulted in a surge of DNN-based mobile applications.
Although traditional architectures, like CNNs and RNNs, have been successfully
integrated into MDs, this is not the case for Transformers, a relatively new
model family that has achieved new levels of accuracy across AI tasks, but
poses significant computational challenges. In this work, we aim to make steps
towards bridging this gap by examining the current state of Transformers'
on-device execution. To this end, we construct a benchmark of representative
models and thoroughly evaluate their performance across MDs with different
computational capabilities. Our experimental results show that Transformers are
not accelerator-friendly and indicate the need for software and hardware
optimisations to achieve efficient deployment.
