AWS introduced the M4 instance type in June 2015. These instances boast up to four times the packet rate of instances that lack enhanced networking; M4 instances are attached to Elastic Block Store (AWS EBS). The instances feature a dedicated network capacity for I/O functionality and regulated latency levels. In addition to the release of the M4 family, AWS reduced the cost of M3 and C4 instances by 5% in half of its regions.
The M4 instance is ideal for applications that implement numerous processes to achieve high consistency levels.