EC2 EBS Optimized Instances – provide a segregated bandwidth for access to EBS – which is really distributed Network Attached Storage (NAS).
Segregated from what? All your other traffic into, within, and out of your VPCs.
Here AWS documentation discussing the subject and importantly it identifies AWS EC2 Instance Types that support EBS Optimized IO – not all Ec2.
https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/EBSOptimized.html
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