The paper presents a more realistic performance model for k-ary n-cube networks under bursty traffic. The validity of the model is demonstrated by comparing analytical results to those obtained through simulation experiments of the actual systems. The proposed model is then used to investigate the implications of bursty traffic on network performance. The results reveal that the performance of k-ary n-cubes degrades considerably in the presence of bursty traffic, stressing the great need for new network architectures that can efficiently support this type of traffic. This study also shows that increasing the number of virtual channels can reduce the impact of bursty traffic and thus improve network performance.