Configurable instance bandwidth weighting - Amazon EBS

Configurable instance bandwidth weighting

Instance bandwidth configuration (IBC) is a feature that enables you to adjust the allocation of network bandwidth between Amazon EBS and VPC networking for an Amazon EC2 instance. This feature can help you optimize performance for workloads with specific bandwidth requirements. Instance bandwidth configuration is supported on some instances only. For more information, see Instance bandwidth weighting configuration.

For EBS performance, using the ebs-1 bandwidth weighting increases the baseline EBS bandwidth by 25 percent while reducing the VPC networking bandwidth by the same absolute amount. This can be beneficial for I/O-intensive workloads that require higher EBS throughput.

When planning your workload, carefully consider your I/O size and patterns. Smaller I/O sizes are generally less affected by bandwidth limitations, while larger I/O sizes or sequential workloads can experience more significant impacts from bandwidth changes. It's crucial to thoroughly test your specific workload to ensure optimal performance with your chosen bandwidth weighting.

Considerations

  • Configurable instance bandwidth is supported on select instance types. For more information, see Supported instance types.

  • Using the ebs-1 bandwidth weighting increases EBS bandwidth up to 25 percent, which can improve the performance of I/O-intensive applications. However, keep in mind that VPC networking bandwidth will be reduced by the same absolute amount (the combined bandwidth specification between EBS and networking does not change).

  • Changes in bandwidth weighting can significantly affect I/O performance. With the vpc-1 bandwidth weighting, network bandwidth is increased, but you might experience lower than expected IOPS for EBS volumes. This is because you might reach the EBS bandwidth limit before the IOPS limit, especially with larger I/O sizes. For example, an instance type that typically supports 240,000 IOPS with 16 KiB I/O size might achieve fewer IOPS when using vpc-1 bandwidth weight due to the decreased EBS bandwidth.

  • Always test your specific workload to ensure that your chosen bandwidth weighting meets your performance needs.

  • You can configure the bandwidth weighting during instance launch or modify it for stopped instances. For more information see Configure bandwidth weighting for your instance.

  • You can configure instance bandwidth weighting at no additional costs.