Finally, we analyzed the training and generation speed of the CLM architectures when increasing the SMILES length, to test their practical applicability when designing bigger molecules. Our analysis highlighted that S4 is as fast as GPT during training (both are approximately 1.3 times faster than LSTM), and the fastest in terms of generation (Figure ), thanks to its dual formulation. This further advocates for the introduction of S4 as an efficient approach for molecule design, that 'makes the best of both worlds' compared to GPT and LSTM.