m5a.xlarge

Analysis

The m5a.xlarge is a general purpose instance in the m5a series with 4 vCPUs and 16 GiB of memory on AMD EPYC 7571 (up to 2.5 GHz), which makes it balanced at 4 GiB of memory per vCPU.

Running it in Mumbai instead of São Paulo saves $120 a month per instance: $0.1110/hour against $0.2760/hour, a 149% spread.

It is the cheapest of the 5 processor variants AWS sells at this size and generation. The m5n.xlarge on Intel Xeon Platinum 8259 (Cascade Lake) costs 38% more, and the m5.xlarge, the m5ad.xlarge and the m5d.xlarge also sit above it.

At $0.1720/hour on demand in US East (N. Virginia), about $126 a month, the m5a.xlarge is one of the cheaper ways to buy general purpose capacity: only 14% of the 354 current general purpose types cost less per vCPU-hour than its $0.0430.

Reserving it for a year with no upfront payment cuts the Linux rate to $0.1080/hour, which beats on demand once it runs more than 63% of the time; three years brings it to $0.0740/hour, 57% below on demand. Windows Server roughly doubles the bill at $0.3560/hour, because the licence is charged per vCPU.

Looking beyond its own line, 5 of 42 current types with 4 vCPUs and similar memory are cheaper. The cheapest of those is the t4g.xlarge on AWS Graviton2 at $0.1344/hour. It is burstable, so it only suits workloads that do not run the CPU flat out.