The pay-as-you-go model is continuing to evolve with customers generating products in a relatively short amount of time. Some of these workloads are ran with a large number of instances within minutes instead of hours.
As of October 2, 2017 in all regions, usage of Linux instances that are launched in On-Demand, Reserved, and Spot form are billed in one-second increments. Similarly, provisioned storage for EBS volumes are billed in one-second increments.
Other services that use per second billing are:
Amazon EMR – Customers add capacity to their EMR clusters in order to get their results more quickly. With per-second billing for the EC2 instances in the clusters, adding nodes is more cost-effective than ever. To learn more, read Amazon EMR Now Supports Per-Second Billing.
AWS Batch – Many of the batch jobs that customers run complete in less than an hour. AWS Batch already launches and terminates Spot Instances. Now with per-second billing for the EC2 instances, batch processing will become even more cost effective.
Elastic GPUs – Usage of Elastic GPUs is billed by the second, with a 1 minute minimum.
Provisioned IOPS – Provisioned IOPS for io1 EBS volumes is billed by the second.
Overall, this is great news and advantageous for AWS customers. It further facilitates Amazon’s paradigm that “you pay only for what you use.” This will not only reduce costs, but foster innovation from developers, architects, and other IT professionals to solve complex problems in the most efficient way.
Other Things to Know
Per-second billing does not apply to instances running Microsoft Windows or Linux distributions that have a separate hourly charge. Marketplace AMIs that do not have a separate hourly charge are eligible for per-second billing.
List prices and Spot Market prices are still listed on a per-hour basis, but bills are calculated down to the second with the usage of decimal points.