Despite the great number of papers that broach the consensus agreement, just a few specifically discuss the structure or the implementation of failure detectors. Some authors have commented on the most traditional detectors, like the heartbeat and interrogation models, with basis in their general characteristics. Although these results could change considering different application scenarios, their differences have not been well evaluated. In fact, at the literature, we have found only one work that compares by simulations different failure detector models. We have chosen to use that paper as basis, and decided to make a comparison among some failure detectors models, using practical systems. In a practical environment, the implementation issues and the operational system can influence both the performance of the detectors and the consensus termination time. This paper presents the evaluation results concerning a specific group of detectors, the heartbeat-like, under several condition, allowing us to identify the behavior of these detectors and their real cost to the system.