Normalization factor for bare metal instances - Amazon EC2 Reserved Instances and Other AWS Reservation Models

Normalization factor for bare metal instances

Instance size flexibility also applies to bare metal instances within the instance family. If you have regional Amazon Linux/Unix Reserved Instances with shared tenancy on bare metal instances, you can benefit from the Reserved Instance savings within the same instance family. The opposite is also true: if you have regional Amazon Linux/Unix Reserved Instances with shared tenancy on instances in the same family as a bare metal instance, you can benefit from the Reserved Instance savings on the bare metal instance.

A bare metal instance is the same size as the largest instance within the same instance family. For example, an i3.metal is the same size as an i3.16xlarge, so they have the same normalization factor.

The .metal instance sizes do not have a single normalization factor. They vary based on the specific instance family. For the most up-to-date list, see Amazon EC2 Instance Types.

Table 4 – Bare metal instance sizes and normalization factors

Instance size Normalization factor
a1.metal 32
c5.metal 192
c5d.metal 192
c5n.metal 144
c6g.metal 128
c6gd.metal 128
g4dn.metal 192
i3.metal 128
i3en.metal 192
m5.metal 192
m5d.metal 192
m5dn.metal 192
m5n.metal 192
m5zn.metal 96
m6g.metal 128
m6gd.metal 128
r5.metal 192
r5b.metal 192
r5d.metal 192
r5dn.metal 192
r5n.metal 192
r6g.metal 128
r6gd.metal 128
x2gd.metal 128
z1d.metal 96

For example, an i3.metal instance has a normalization factor of 128. If you purchase an i3.metal default tenancy Amazon Linux/Unix Reserved Instance in the US East (N. Virginia) Region, the billing benefit can apply as follows:

  • If you have one running i3.16xlarge in your account in that Region, the billing benefit is applied in full to the i3.16xlarge instance (i3.16xlarge normalization factor = 128).

  • Or, if you have two running i3.8xlarge instances in your account in that Region, the billing benefit is applied in full to both i3.8xlarge instances (i3.8xlarge normalization factor = 64).

  • Or, if you have four running i3.4xlarge instances in your account in that Region, the billing benefit is applied in full to all four i3.4xlarge instances (i3.4xlarge normalization factor = 32).

The opposite is also true. For example, if you purchase two i3.8xlarge default tenancy Amazon Linux/Unix Reserved Instances in the US East (N. Virginia) Region, and you have one running i3.metal instance in that Region, the billing benefit is applied in full to the i3.metal instance.