Posted On: Nov 25, 2019

Starting today, Amazon EC2 is introducing the ability for customers to choose an Unlimited mode preference using CLI and SDK at the account level for T3, T3a, and T2 instance types. The new API will enable customers to perform a one time action of setting Unlimited or Standard mode as the default preference for all T3, T3a, and T2 instance launches.

The latest generation general purpose burstable instance types, T3 and T3a, start in Unlimited mode by default, giving users the ability to sustain high CPU performance over any desired time frame while keeping cost as low as possible. In the case you want to launch T3 instances in Standard mode by default, you can now use the modify-default-credit-specification to set your default preference to Standard mode. T2 instances are launched in Standard mode by default. Previously to run T2 in Unlimited mode, you would have had to launch T2 with the Unlimited credit-specification parameter or modify the T2 instances credit-specification to Unlimited after launch. Now, T2 customers can run in Unlimited mode by default by using modify-default-credit-specification to set the default account preference to Unlimited mode. For more details on Unlimited mode for T3, T3a, and T2 instances, see our EC2 documentation page here.

The account level Unlimited mode preference is set per AWS account, region, and instance family. Once you set your Unlimited mode preference, all new T3, T3a, or T2 instance launches from that AWS account will be launched with your preference by default. All existing running and stopped T instances will maintain their current credit specification. For more details about the two new APIs modify-default-credit-specification and get-default-credit-specification see our API detail pages here:


Note: Account level Unlimited mode preference will only affect instances launched via CLI or SDK.