I have posted a question on stackoverflow about sudden reduction in application throughout . I also follows up on this conversation with AWS support and Following is the gist of conversation with AWS Support - tl dr: AWS instances my team was using was not set with enhanced networking capabilities to be able to get max n/w performance (i.e. 10 gigabits on c4.8xlarge instance). For example ixgbevf on test-aws-am was not set to 2.14.2. Long Version: The test in question is a static html page. GET request, no complicated logic, No EBS, DJ-CTS etc. What n/w capabilities should we experience when instance does not satisfy enhanced networking capabilities? AWS Support: We really do not have specific numbers because that varies... by a lot of factors (time of day, other instances sharing network in same location.. and several other factors... What we do, is to advice customers to do benchmarking tests to confirm that the instances meet the performance expectations....