c5a.8xlarge

Analysis

The c5a.8xlarge is a compute optimized instance in the c5a series with 32 vCPUs and 64 GiB of memory on AMD EPYC 7R32 (up to 3.3 GHz), which makes it compute-heavy at 2 GiB of memory per vCPU.

Running it in Mumbai instead of São Paulo saves $829 a month per instance: $0.7520/hour against $1.89/hour, a 151% spread.

It is the cheapest of the 2 processor variants AWS sells at this size and generation. The c5ad.8xlarge on AMD EPYC 7R32 costs 12% more, and no others also sit above it.

At $1.23/hour on demand in US East (N. Virginia), about $899 a month, the c5a.8xlarge is one of the cheaper ways to buy compute optimized capacity: only 14% of the 291 current compute optimized types cost less per vCPU-hour than its $0.0385.

Reserving it for a year with no upfront payment cuts the Linux rate to $0.7760/hour, which beats on demand once it runs more than 63% of the time; three years brings it to $0.5320/hour, 57% below on demand. Windows Server roughly doubles the bill at $2.70/hour, because the licence is charged per vCPU.

Looking beyond its own line, 4 of 28 current types with 32 vCPUs and similar memory are cheaper. The cheapest of those is the c6g.8xlarge on AWS Graviton2 at $1.09/hour.