r5.4xlarge

Analysis

The r5.4xlarge is a memory optimized instance in the r5 series with 16 vCPUs and 128 GiB of memory on Intel Xeon Platinum 8175 (up to 3.1 GHz), which makes it memory-heavy at 8 GiB of memory per vCPU.

Within the same generation and size, the r5a.4xlarge on AMD EPYC 7571 costs $0.9040/hour, 10% less ($75.92 a month). The other variants are the r5ad.4xlarge at $1.05, the r5d.4xlarge at $1.15 and the r5n.4xlarge at $1.19.

At $1.01/hour on demand in US East (N. Virginia), about $736 a month, the r5.4xlarge is one of the cheaper ways to buy memory optimized capacity: only 16% of the 385 current memory optimized types cost less per vCPU-hour than its $0.0630.

Running it in N. Virginia instead of São Paulo saves $438 a month per instance: $1.01/hour against $1.61/hour, a 60% spread.

It is 5.3% cheaper than the older r4.4xlarge on Intel Xeon E5-2686 v4 (Broadwell), so staying on the previous generation costs more as well as being slower.

Looking beyond its own line, 6 of 42 current types with 16 vCPUs and similar memory are cheaper. The cheapest of those is the r6g.4xlarge on AWS Graviton2 at $0.8064/hour.

Reserving it for a year with no upfront payment cuts the Linux rate to $0.6350/hour, which beats on demand once it runs more than 63% of the time; three years brings it to $0.4350/hour, 57% below on demand. Windows Server roughly adds 73% to the bill at $1.74/hour, because the licence is charged per vCPU.