We present a comparison of the physical properties of a rest-frame 250-μm-selected sample of massive, dusty galaxies from 0 1 SMGs have an average star formation rate (SFR) of 390+80 -70 M⊙ yr-1, which is 120 times that of the low-redshift sample matched in stellar mass to the SMGs (SFR=3.3±0.2M⊙ yr-1). The SMGsharbour a substantialmass of dust (1.2+0.3 -0.2 ×109 M⊙), compared to (1.6 ± 0.1) ×108 M⊙ for low-redshift dusty galaxies. At low redshifts, the dust luminosity is dominated by the diffuse interstellar medium, whereas a large fraction of the dust luminosity in SMGs originates from star-forming regions. At the same dust mass, SMGs are offset towards a higher SFR compared to the low-redshift H-ATLAS galaxies. This is not only due to the higher gas fraction in SMGs but also because they are undergoing a more efficient mode of star formation, which is consistent with their bursty star formation histories. The offset in SFR between SMGs and low-redshift galaxies is similar to that found in CO studies, suggesting that dust mass is as good a tracer of molecular gas as CO. © 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.