m4.2xlarge

Analysis

The m4.2xlarge is a general purpose instance in the m4 series with 8 vCPUs and 32 GiB of memory on Intel Xeon E5-2676 v3 (Haswell) (up to 2.4 GHz), which makes it balanced at 4 GiB of memory per vCPU.

Running it in N. Virginia instead of São Paulo saves $172 a month per instance: $0.4000/hour against $0.6360/hour, a 59% spread.

Reserving it for a year with no upfront payment cuts the Linux rate to $0.2478/hour, which beats on demand once it runs more than 62% of the time; three years brings it to $0.1728/hour, 57% below on demand. Windows Server roughly doubles the bill at $0.7680/hour, because the licence is charged per vCPU.

On demand it costs $0.4000/hour in US East (N. Virginia), $292 a month if left running, which puts it mid-table for general purpose types at the 35th percentile per vCPU ($0.0500 per vCPU-hour) and the 35th percentile per GiB ($0.0125 per GiB-hour).

The newer m5.2xlarge on Intel Xeon Platinum 8175 is 4.0% cheaper at $0.3840/hour, which makes the m4.2xlarge hard to justify for new deployments.

Looking beyond its own line, 14 of 42 current types with 8 vCPUs and similar memory are cheaper. The cheapest of those is the t4g.2xlarge on AWS Graviton2 at $0.2688/hour. It is burstable, so it only suits workloads that do not run the CPU flat out.