M4 instances deliver significant processing power with custom 2.4 GHz Xeon E5-2676 v3 Haswell processors, offer dedicated bandwidth to Amazon Elastic Block Store , and provide Enhanced Networking for higher packet per second performance, lower network jitter, and lower network latencies. M4 with Enhanced Networking delivers up to 4 times the packet rate of instances without Enhanced Networking, while ensuring consistent latency, even when under high network IO.