Effective scheduling is critical for the performance of an application launched onto the Grid environment. Deriving efficient algorithms for this scheduling has always been a challenging research area. Many scheduling algorithms have been proposed, studied and compared but there are few studies comparing their performance in Grid environments. The Grid environment has the unique property of drastic cost differences between inter-cluster and the intra-cluster data transfers. In this paper, we compare several scheduling algorithms that represent two major schemes. We further analyze the results to show how different resource environments and workflow application structures affect the algorithms' performances, and suggest directions for future research in Grid schedulers.