c5a.large

Analysis

The c5a.large is a compute optimized instance in the c5a series with 2 vCPUs and 4 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 $51.83 a month per instance: $0.0470/hour against $0.1180/hour, a 151% spread.

It is the cheapest of the 5 processor variants AWS sells at this size and generation. The c5n.large on Intel Xeon Platinum 8124M costs 40% more, and the c5.large, the c5ad.large and the c5d.large also sit above it.

At $0.0770/hour on demand in US East (N. Virginia), about $56.21 a month, the c5a.large 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 $0.0490/hour, which beats on demand once it runs more than 64% of the time; three years brings it to $0.0330/hour, 57% below on demand. Windows Server roughly doubles the bill at $0.1690/hour, because the licence is charged per vCPU.

Looking beyond its own line, 9 of 36 current types with 2 vCPUs and similar memory are cheaper. The cheapest of those is the t4g.medium on AWS Graviton2 at $0.0336/hour. It is burstable, so it only suits workloads that do not run the CPU flat out.