Selecting Instance Types#

An instance is a server hosted by a cloud provider and instance types (or machine types) are defined by combinations of CPU, memory, storage, and networking capacity (see GCP supported instance types and AWS supported instance types for more details).

Specifying memory and CPU#

When you create a cluster, you can provide a range of required resources, and Coiled will select available, compatible instance types for you. In the following example, Coiled will select instance types with between 2 and 8 CPUs and between 32 and 64 GiB of memory:

from coiled import Cluster
from distributed import Client

cluster = Cluster(worker_cpu=[2, 8], worker_memory=["32GiB", "64GiB"])
client = Client(cluster)

When Coiled identifies a number of compatible instance types, they are prioritized in order of lowest to highest estimated cost.

Requesting specific instance types#

To allow for more fine-grain control of the type of cluster you create, you can provide a list of specific instance types for the scheduler and workers using the scheduler_vm_types and worker_vm_types keyword arguments.


Coiled also supports using ARM (Graviton) instances on AWS (see Using ARM on Coiled).

For example:

import coiled

cluster = coiled.Cluster(
    scheduler_vm_types=["t3.large", "t3.xlarge"],
    worker_vm_types=["m5n.large", "m5zn.large"],

It’s recommended you specify more than one instance type in your list to avoid instance availability issues in the cloud provider and region that you are using Coiled. Lists of instance types are prioritized in order of decreasing priority.

Allowable Instance Types#

You can use coiled.list_instance_types() to see a list of all allowed instance types for your configured cloud provider. For example:

import coiled


For more details on supported instance types see

You can specify a single keyword argument or a combination (e.g. cores, memory and gpus) to filter the results.

import coiled

# Filter instances that have 4 cores only

# Filter instances by cores and memory
coiled.list_instance_types(cores=2, memory="8 Gib")

You can also provide list_instance_types with a range of values, for example:

import coiled

coiled.list_instance_types(cores=[2, 8])

You might be also interested in the tutorial on GPUs.