Several load balancing algorithms available to balance load in cloud data centers along with various service broker policies to select data centers based on the origin of user request. The user response time and data center request servicing time are important metrics to analyze the performance of cloud from the user perspective. We investigate the performance of Round Robin, and throttle based load balancing algorithms along with service broker policies such as closest data center and optimize response time with different user grouping factor in cloud environment. i.e., when the user grouping factor is set as 100 and 500. We present the results of simulation with various configurations as mentioned above, performed in CloudAnalyst, an open source tool. The results obtained would help the researchers, academicians, industrialist and cloud Vendors to effectively design their applications that might be deployed in cloud. © BEIESP.