Burstable instances (t5/t6) support both standard and unlimited modes to meet different business requirements. Learn how to view, enable, or disable unlimited mode for your instances.
Background information
Standard mode: The performance of a burstable instance is constrained by its CPU credits. After the initial and accrued CPU credits are depleted, the instance's performance cannot exceed its baseline performance.
Unlimited mode: A burstable instance can burst beyond its available CPU credit limits. It can maintain CPU utilization above its baseline performance at any time by overdrawing or paying for CPU credits.
In unlimited mode, a burstable instance may incur additional fees. For more information, see Additional fees.
The system automatically selects a performance mode for a burstable instance in the following scenarios:
When you create a burstable instance, it uses standard mode by default.
If a burstable instance is in the Stopped state and has economical mode enabled, it defaults to standard mode after it is started.
If a burstable instance in the Stopped state does not have economical mode enabled, its performance mode is unchanged when you restart it.
If your account has an overdue payment, unlimited mode is automatically disabled for your burstable instances. It is automatically re-enabled after you pay the bill.
View the performance mode
Go to ECS console - Instances.
In the top navigation bar, select the region and resource group of the resource that you want to manage.
(Optional) If the Unlimited Mode column is not displayed on the Instance page, customize the instance list.
Click the
icon in the upper-right corner. In the Instance List Settings dialog box, find Unlimited Mode in the Columns Not Displayed section, click the
icon to the right, and then click Continue.
In the Unlimited Mode column, view the mode of the burstable instance.
Disabled: The instance is in standard mode.
Enabled: The instance is in unlimited mode.
Enable unlimited mode
If your business occasionally experiences high CPU usage spikes, you can enable unlimited mode.
Make sure that the burstable instance is in the Running state. Otherwise, you cannot switch its performance mode.
Go to ECS console - Instances.
Find the burstable instance in standard mode and choose one of the following methods:
For a single instance: Choose
> Instance Attributes > Enable Unlimited Mode in the Actions column. 
For one or more instances: Select the instances and choose in the lower-left corner of the Instance page.
In the Enable Unlimited Mode dialog box, select I am aware of the costs and risks. and then click Confirm.
Disable unlimited mode
If the instance's baseline CPU performance meets your business requirements, you can disable unlimited mode.
Make sure that the burstable instance is in the Running state. Otherwise, you cannot switch its performance mode.
Go to ECS console - Instances.
Find the burstable instance in unlimited mode and choose one of the following methods:
For a single instance: Choose
> Instance Attributes > Disable Unlimited Mode in the Actions column. 
For one or more instances: Select the instances and choose in the lower-left corner of the Instance page.
In the Disable Unlimited Mode dialog box, click Confirm.
FAQs
How do I view CPU credit changes?
On the instance details page of a burstable instance (t5/t6), click the Monitoring tab to view Consumed CPU Credits, Accrued CPU Credits, Surplus CPU Credit, and Advance CPU Credits.
Be aware that additional fees may apply in unlimited mode. The billing rules are as follows:
If an instance uses up its advance CPU credits and continues to consume overdrawn CPU credits, you are billed hourly for the overdrawn credits.
If an instance consumes advance CPU credits and then, before these credits are paid back, you stop the instance (with economical mode enabled), modify its configuration, release it, or switch it to standard mode, you are charged a one-time fee for the used advance CPU credits.
For more information, see Billing.
How do I check when unlimited mode was enabled?
Go to the Operation Logs page for ECS. For Operation Name, select ModifyInstanceAttribute, and then click View Details for a specific event. In the operation details, a CreditSpecification parameter set to Unlimited indicates that unlimited mode was enabled.
