Not only the server need to be able to respond fast enough, JMeter must be able to send requests fast enough as well. Default JMeter configuration is suitable for tests development and debugging and creating some load (rather limited though), you need to properly tune your JMeter instance in order to fully utilize your machine resources If your single machine is not powerful enough to conduct the required load it's possible to run JMeter in distributed mode using as many load generators as needed in order to create the necessary number of virtual users/requests per second