c5a.12xlarge

Analysis

The c5a.12xlarge is a compute optimized instance in the c5a series with 48 vCPUs and 96 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 $1,244 a month per instance: $1.13/hour against $2.83/hour, a 151% spread.

It is the cheapest of the 4 processor variants AWS sells at this size and generation. The c5d.12xlarge on Intel Xeon Platinum 8275L costs 25% more, and the c5.12xlarge and the c5ad.12xlarge also sit above it.

At $1.85/hour on demand in US East (N. Virginia), about $1,349 a month, the c5a.12xlarge 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 $1.16/hour, which beats on demand once it runs more than 63% of the time; three years brings it to $0.7980/hour, 57% below on demand. Windows Server roughly doubles the bill at $4.06/hour, because the licence is charged per vCPU.

Looking beyond its own line, 4 of 30 current types with 48 vCPUs and similar memory are cheaper. The cheapest of those is the c6g.12xlarge on AWS Graviton2 at $1.63/hour.