c8a.4xlarge

Analysis

The c8a.4xlarge is a compute optimized instance in the c8a series with 16 vCPUs and 32 GiB of memory on AMD EPYC 9R45 (up to Up to 4.5 GHz), which makes it compute-heavy at 2 GiB of memory per vCPU.

Within the same generation and size, the c8g.4xlarge on AWS Graviton4 costs $0.6381/hour, 26% less ($164 a month), though switching means rebuilding software for arm64. The other variants are the c8i-flex.4xlarge at $0.7122, the c8i.4xlarge at $0.7497 and the c8gd.4xlarge at $0.7838.

Running it in N. Virginia instead of Tokyo saves $163 a month per instance: $0.8622/hour against $1.09/hour, a 26% spread. It is not offered in Canada Central, São Paulo, London, Mumbai, Singapore and Sydney, so plan around that if you need a presence there.

On demand it costs $0.8622/hour in US East (N. Virginia), $629 a month if left running, which puts it mid-table for compute optimized types at the 69th percentile per vCPU ($0.0539 per vCPU-hour) and the 73rd percentile per GiB ($0.0269 per GiB-hour).

Looking beyond its own line, 22 of 31 current types with 16 vCPUs and similar memory are cheaper. The cheapest of those is the c6g.4xlarge on AWS Graviton2 at $0.5440/hour.

Compared with the previous generation, it costs 5.0% more than the c7a.4xlarge on AMD EPYC 9R14 ($29.96 more a month per instance), in exchange for the newer processor.