c6i.16xlarge

Analysis

The c6i.16xlarge is a compute optimized instance in the c6i series with 64 vCPUs and 128 GiB of memory on Intel Xeon 8375C (Ice Lake) (up to 3.5 GHz), which makes it compute-heavy at 2 GiB of memory per vCPU.

Within the same generation and size, the c6g.16xlarge on AWS Graviton2 costs $2.18/hour, 20% less ($397 a month), though switching means rebuilding software for arm64. The other variants are the c6a.16xlarge at $2.45, the c6gd.16xlarge at $2.46 and the c6gn.16xlarge at $2.76.

At $2.72/hour on demand in US East (N. Virginia), about $1,986 a month, the c6i.16xlarge 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 $1,075 a month per instance: $2.72/hour against $4.19/hour, a 54% spread.

Reserving it for a year with no upfront payment cuts the Linux rate to $1.80/hour, which beats on demand once it runs more than 66% of the time; three years brings it to $1.20/hour, 56% below on demand. Windows Server roughly doubles the bill at $5.66/hour, because the licence is charged per vCPU.

The newer c7i.16xlarge on Intel Xeon Scalable (Sapphire Rapids) is 5.0% dearer at $2.86/hour.