m5.8xlarge

Analysis

The m5.8xlarge is a general purpose instance in the m5 series with 32 vCPUs and 128 GiB of memory on Intel Xeon Platinum 8175 (up to 3.1 GHz), which makes it balanced at 4 GiB of memory per vCPU.

Within the same generation and size, the m5a.8xlarge on AMD EPYC 7571 costs $1.38/hour, 10% less ($117 a month). The other variants are the m5ad.8xlarge at $1.65, the m5d.8xlarge at $1.81 and the m5n.8xlarge at $1.90.

Running it in N. Virginia instead of São Paulo saves $666 a month per instance: $1.54/hour against $2.45/hour, a 59% spread.

On demand it costs $1.54/hour in US East (N. Virginia), $1,121 a month if left running, which puts it mid-table for general purpose types at the 29th percentile per vCPU ($0.0480 per vCPU-hour) and the 28th percentile per GiB ($0.0120 per GiB-hour).

Reserving it for a year with no upfront payment cuts the Linux rate to $0.9680/hour, which beats on demand once it runs more than 63% of the time; three years brings it to $0.6640/hour, 57% below on demand. Windows Server roughly doubles the bill at $3.01/hour, because the licence is charged per vCPU.

Looking beyond its own line, 7 of 37 current types with 32 vCPUs and similar memory are cheaper. The cheapest of those is the m6g.8xlarge on AWS Graviton2 at $1.23/hour.