c5.18xlarge

Analysis

The c5.18xlarge is a compute optimized instance in the c5 series with 72 vCPUs and 144 GiB of memory on Intel Xeon Platinum 8124M (up to 3.4 GHz), which makes it compute-heavy at 2 GiB of memory per vCPU.

Nothing else with 72 vCPUs and similar memory is cheaper: among 2 current same-shape types it has the lowest on-demand price.

It is the cheapest of the 3 processor variants AWS sells at this size and generation. The c5n.18xlarge on Intel Xeon Platinum 8124M costs 27% more, and the c5d.18xlarge also sit above it.

At $3.06/hour on demand in US East (N. Virginia), about $2,234 a month, the c5.18xlarge is one of the cheaper ways to buy compute optimized capacity: only 24% of the 291 current compute optimized types cost less per vCPU-hour than its $0.0425.

Running it in Mumbai instead of São Paulo saves $1,209 a month per instance: $3.06/hour against $4.72/hour, a 54% spread.

Reserving it for a year with no upfront payment cuts the Linux rate to $1.93/hour, which beats on demand once it runs more than 63% of the time; three years brings it to $1.28/hour, 58% below on demand. Windows Server roughly doubles the bill at $6.37/hour, because the licence is charged per vCPU.