A Distributed Virtual Environment (DVE) enables geographically distributed clients to interact with each other in a simulated environment. Due to the distributed architecture of DVEs, it is generally not easy to evaluate the performance of DVEs. In this paper, we propose a consistency model based on a metric called time-space inconsistency. The model relates a human participant's perception to the characteristic parameters of a DVE. Based on the model, the performance of a DVE can be easily evaluated without the actual execution of the DVE application, which is especially useful in the designing stage of a DVE. A Ping-Pong game is developed to verify the proposed model. Experiment results show that the model is effective in evaluating the performance of the game.