View the CPU options for your instance

You can view the CPU options for an existing instance in the Amazon EC2 console or by describing the instance using the AWS CLI.

Console

To view the CPU options for an instance using the console

1. Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

2. In the left navigation pane, choose Instances and select the instance.

3. On the Details tab, under Host and placement group, find Number of vCPUs.

AWS CLI

To view the CPU options for an instance (AWS CLI)

Use the describe-instances command.

aws ec2 describe-instances --instance-ids i-123456789abcde123

...
    "Instances": [
        {
            "Monitoring": {
                "State": "disabled"
            }, 
            "PublicDnsName": "ec2-198-51-100-5.eu-central-1.compute.amazonaws.com", 
            "State": {
                "Code": 16, 
                "Name": "running"
            }, 
            "EbsOptimized": false, 
            "LaunchTime": "2018-05-08T13:40:33.000Z", 
            "PublicIpAddress": "198.51.100.5", 
            "PrivateIpAddress": "172.31.2.206", 
            "ProductCodes": [], 
            "VpcId": "vpc-1a2b3c4d", 
            "CpuOptions": {
                "CoreCount": 34, 
                "ThreadsPerCore": 1
            }, 
            "StateTransitionReason": "", 
            ...
        }
    ]
...

In the output that's returned, the CoreCount field indicates the number of cores for the instance. The ThreadsPerCore field indicates the number of threads per core.

Alternatively, connect to your instance and use a tool such as lscpu to view the CPU information for your instance.

You can use AWS Config to record, assess, audit, and evaluate configuration changes for instances, including terminated instances. For more information, see Getting Started with AWS Config in the AWS Config Developer Guide.