r5a.4xlarge

Analysis

The r5a.4xlarge is a memory optimized instance in the r5a series with 16 vCPUs and 128 GiB of memory on AMD EPYC 7571 (up to 2.5 GHz), which makes it memory-heavy at 8 GiB of memory per vCPU.

Running it in Mumbai instead of São Paulo saves $639 a month per instance: $0.5720/hour against $1.45/hour, a 153% spread.

At $0.9040/hour on demand in US East (N. Virginia), about $660 a month, the r5a.4xlarge is one of the cheaper ways to buy memory optimized capacity: only 5% of the 385 current memory optimized types cost less per vCPU-hour than its $0.0565.

It is the cheapest of the 5 processor variants AWS sells at this size and generation. The r5n.4xlarge on Intel Xeon Platinum 8259 (Cascade Lake) costs 32% more, and the r5.4xlarge, the r5ad.4xlarge and the r5d.4xlarge also sit above it.

It is size 4 of 8 in the r5a series. Stepping up to the r5a.8xlarge gives 32 vCPUs and 256 GiB for $660 more a month. Dropping to the r5a.2xlarge saves $330 a month.

Reserving it for a year with no upfront payment cuts the Linux rate to $0.5700/hour, which beats on demand once it runs more than 63% of the time; three years brings it to $0.3910/hour, 57% below on demand. Windows Server roughly adds 81% to the bill at $1.64/hour, because the licence is charged per vCPU.