Specifying a minimum CPU Platform for VM instances

This document explains how to create or update a virtual machine instance to use a baseline minimum CPU platform (minCpuPlatform) whenever available.

Google datacenters offer Intel Xeon-based host machines containing Sandy Bridge, Ivy Bridge, Haswell, Broadwell, and Skylake CPU Platforms. Each CPU platform supports incremental features like AVX-2, AVX-512, and so on. Some fundamental systems-related features like clock speed and memory access seek time can vary across CPU platforms. Different zones support multiple CPU Platforms, and you can select a CPU platform for your VM instances that supports the specific needs of your workloads using minimum platform selection.

To learn about the available CPU platforms for each zone, read the CPU Platforms and Regions and Zones documentation.

Before you begin

When to select a minimum CPU platform

More than likely, you do not need to select a minimum CPU platforms for your VMs. Each Compute Engine zone has a default CPU platform, listed in the Regions and Zones documentation. Any newly created VM without a minimum CPU specification will get the default CPU Platform automatically.

Google recommends that you only select a minimum CPU platform when it introduces significant performance gains for your workload, or provides certain capabilities such as AVX2, AVX512, or MPX utilized by your code. Selecting a specific minimum CPU platform for your VM introduces additional constraints that affect your ability to start VMs in certain zones where some CPU platforms are in limited supply.

How selecting a minimum CPU platform works

When you specify a minimum CPU platform:

  • Compute Engine always uses the minimum CPU platform where available.

  • If Compute Engine retires a CPU platform from a zone, your VM can continue to run on a better CPU Platform available in that zone after you stop and restart the VM. Retiring CPU platforms is an infrequent situation and you will be notified of ahead of time.

Once you select a minimum CPU platform for a VM:

  • Your VM will use this CPU platform, unless you stop the VM and change the CPU platform.
  • Upon live migration, your VM retains the same selected CPU platform.
  • Occasionally, Google might update the default CPU platform for a zone. Read Retiring or upgrading a default CPU platform for more information.

Retiring or upgrading a default CPU platform

Occasionally, Google will retire an older CPU platform or update the default CPU platform in a particular zone because:

  • A zone grows in capacity over time and proactively switches to a newer CPU platform as the platform becomes available.
  • Every 3 to 5 years, Google replaces older CPU platforms with newer platforms, and updates the default CPU platform to the next newest platform available in that zone.

At any time, when a new region or zone is built, it will use the newest CPU platform at the time.

When a zone is retired or a default CPU platform for a zone changes, Google will provide advance notice to affected customers with a detailed timeline and specific instructions to transition to the newer platform.

VMs will never use a platform that is older than the minimum CPU platform you specify and the cost of the VM will not change if Compute Engine transitions your VM to a more recent platform.

Specifications

Limitations

  • f1-small and g1-small predefined machine types are shared-core general purpose VMs. These do not have the CPU platform selection options.

Availability

The availability of specific CPU platforms varies across zones, based on the hardware available in each zone. The following is a list of supported minimum CPU platforms and the valid syntax for each platform:

  • Intel Xeon (Skylake) processors: "Intel Skylake"
  • Intel Xeon E5 (Sandy Bridge) processors: "Intel Sandy Bridge"
  • Intel Xeon E5 v2 (Ivy Bridge) processors: "Intel Ivy Bridge"
  • Intel Xeon E5 v3 (Haswell) processors: "Intel Haswell"
  • Intel Xeon E5 v4 (Broadwell) processors: "Intel Broadwell"
  • Intel Xeon (Cascade Lake) processors: "Intel Cascade Lake"

Only certain zones contain multiple CPU platforms and are available for minimum CPU platform selection. If you are using sole-tenant nodes, each node uses the CPU platform corresponding to the node type you defined in the node template. As a result, you cannot specify a minimum CPU platform for VMs that use sole-tenant nodes.

You can view a list of supported platforms for a specific zone using the gcloud compute zones describe command or by making a request to the API.

gcloud

To see the CPU platforms in your zone:

gcloud compute zones describe [ZONE]

For example, the output from this command lists the CPU platforms for the us-west1-a zone:

$ gcloud compute zones describe us-west1-a
availableCpuPlatforms:
- Intel Skylake
- Intel Broadwell
...

API

In the API, make a GET request to the zone in question:

GET https://compute.googleapis.com/compute/v1/projects/myproject/zones/[ZONE]

The response contains a list of support CPU platforms for that zone. For example:

{
 "kind": "compute#zone",
 "id": "2210",
 "creationTimestamp": "2016-06-10T09:30:55.189-07:00",
 "name": "us-west1-a",
 "description": "us-west1-a",
 "status": "UP",
 "region": "https://www.googleapis.com/compute/v1/projects/myproject/regions/us-west1",
 "selfLink": "https://www.googleapis.com/compute/v1/projects/myproject/zones/us-west1-a",
 "availableCpuPlatforms": [
  "Intel Broadwell",
  "Intel Haswell"
 ]
}

Selecting a minimum CPU platform for a new VM

You can specify a minimum CPU platform during instance creation.

Console

  1. Go to the VM instances page.

    Go to the VM instances page

  2. If prompted, select your project and click Continue.
  3. Click the Create instance button.
  4. Under the Machine configuration section section, click CPU platform and GPU.
  5. Select an option from the CPU platform drop down menu.
  6. Continue with the rest of the instance creation process.

gcloud

To create a new VM with a min CPU platform using the gcloud command-line tool, provide the new --min-cpu-platform flag. When specifying the CPU platform, provide the platform using the friendly name, such as Intel Broadwell and Intel Haswell. Use the available zones section to determine which platforms are available for each zone.

For example, to specify a minimum CPU platform of Intel Haswell:

gcloud compute instances create example-instance \
    --zone europe-west1-b \
    --min-cpu-platform "Intel Haswell"

If you want clear the minimum CPU platform specification, set --min-cpu-platform to AUTOMATIC.

API

In the Compute Engine API, include the minCpuPlatform property as part of the request body. The value for minCpuPlatform must be the friendly name for the platform, such as Intel Haswell, Intel Broadwell, and Intel Sandy Bridge.

For example, a request body might look like this:

"name": "[INSTANCE_NAME]",
"machineType": "zones/[ZONE]/machineTypes/[MACHINE_TYPE]",
"minCpuPlatform": "Intel Haswell",
"networkInterfaces": [{
  "accessConfigs": [{
    "type": "ONE_TO_ONE_NAT",
    "name": "External NAT"
   }],
  "network": "global/networks/default"
}],
"disks": [{
   "autoDelete": "true",
   "boot": "true",
   "type": "PERSISTENT",
   "initializeParams": {
      "sourceImage": "projects/[IMAGE_PROJECT]/global/images/family/[IMAGE]"
   }
 }]

If you want clear the minimum CPU platform specification, set minCpuPlatform to AUTOMATIC.

Setting a minimum CPU platform for a stopped VM

You can set a minimum CPU platform for an existing instance if you first stop the instance.

After stopping the instance, follow the instructions below to set a minimum CPU platform and then make sure to restart the instance.

Console

  1. Go to the VM instances page.

    Go to the VM Instances page

  2. If prompted, select your project and click Continue.
  3. Select the stopped instance that you want to change.
  4. Click Edit to edit the instance.
  5. Under the Machine configuration section, click CPU platform and GPU.
  6. Select an option from the CPU platform drop down menu.
  7. Save your changes.
  8. Restart the instance.

gcloud

Use the update subcommand, followed by the --min-cpu-platform flag. Specify the friendly name of the platforms, such as Intel Haswell, Intel Broadwell, and Intel Sandy Bridge. For example:

gcloud compute instances update [INSTANCE_NAME] \
    --min-cpu-platform "Intel Haswell"

API

To set the minimum CPU platform in the API, make a POST request to the setMinCpuPlatform method and set the minCpuPlatform property in the request body. The value for the property is the friendly name for the CPU platform, such as Intel Haswell, Intel Broadwell, and Intel Sandy Bridge. For example:

POST https://compute.googleapis.com/compute/v1/projects/[PROJECT_ID]/zones/[ZONE]/instances/[INSTANCE]/setMinCpuPlatform

{
  "minCpuPlatform": "Intel Haswell"
}

Specifying a minimum CPU platform in instance templates

If you use managed instance groups, you can specify a minimum CPU platform for VM instances within a managed instance group.

To specify a minimum CPU platform, create an instance template that includes the minCpuPlatform property.

Console

  1. Go to the Instance templates page.

    Go to the Instance templates page

  2. If prompted, select your project and click Continue.
  3. Click Create instance template.
  4. Under the Machine configuration section, click CPU platform and GPU.
  5. Select an option from the CPU platform drop down menu.
  6. Continue with the instance template creation process.

gcloud

Using the gcloud tool, provide the --min-cpu-platform flag when creating an instance template. For example:

gcloud compute instance-templates create example-template \
    --min-cpu-platform "Intel Haswell"

API

In the API, add the minCpuPlatform as part of your request to create a new instance template in the API.

For example, the following instance template contains the minimum required fields for creating a new template with the addition of the minCpuPlatform property:

{
"name": "example-template",
"properties": {
  "machineType": "zones/us-central1-a/machineTypes/n1-standard-2",
  "minCpuPlatform": "Intel Haswell",
  "networkInterfaces": [
    {
      "network": "global/networks/default",
      "accessConfigs":
      [
        {
          "name": "external-IP",
          "type": "ONE_TO_ONE_NAT"
        }
      ]
    }
  ],
  "disks":
  [
    {
      "type": "PERSISTENT",
      "boot": true,
      "mode": "READ_WRITE",
      "initializeParams":
      {
        "sourceImage": "projects/debian-cloud/global/images/family/debian-8"
      }
    }
  ]
  }
}

What's next