The aim of this work is to measure and analyze the impact of aspect-oriented programming on software performance. Thus we hypothesized as follow: adding aspects to the original base program will affect its performance because of the overhead caused by the control flow switching, and that incremental effect on performance is more obvious as the number of join points increases. To confirm (or reject) our hypotheses we carried out a case study of two concurrent software architectures: Half-Sync/Half-Asyn (HS/HA) and Leader/Followers (LFs). Aspects were extracted and encapsulated, and the aspect-enabled program was compared to the base program for performance. Our results show that aspect-oriented approach does not have significant effect on the performance and that in some cases, aspect-oriented program even outperform the non-aspect program. Additionally, introduction of a large number of joint points does not have significant effect on the performance.