We have obtained spectral and timing data on GX 3+1 and Ser X-1 .
Both sources were observed simultaneously with BeppoSAX and RXTE .
The RXTE data is used to provide power spectra and colour-colour diagrams in order to constrain the state ( and thus track \dot { M } ) the sources are in .
The BeppoSAX data provide the broad-band spectra .
The spectra of both sources are reasonably well-fit using a model consisting of a disk-blackbody , a comptonized component and a Fe line , absorbed by interstellar absorption .
The electron temperature ( kT _ { e } ) of the Comptonizing plasma is in both cases \sim 2.5 keV .
This implies that no strong high-energy tail from the Comptonized component is present in either of the sources .
We discuss the similarities between these burst sources and the luminous X-ray sources located in globular clusters .
We find that the spectral parameters of the comptonized component provide information about the mass-accretion rate , which agrees well with estimates from the timing and spectral variations .