The high use of system calls in many applications has motivated research works focusing on reducing the overhead caused by these calls. In this work we implement three types of compound system calls, which are evaluated experimentally by taking into account their execution time in systems with 1 to 8 cores. We also investigate the system calls running in both physical and virtual machines. All proposed compound system calls present performance gains when compared to their conventional counterparts. The results indicate reduction in the execution time up to 58 percent. The dataset obtained through controlled experiments is analyzed using ANOVA and Tukey tests. We also verify that the highest improvements occur in the non-virtualized environment.