r5d.12xlarge is AWS's memory-optimized EC2 size at 48 vCPU and 384 GiB. In the name, "r" stands for RAM, "5" is the generation, "d" marks local NVMe storage and "12xlarge" is the size within the r5d family. It runs on Intel Xeon Platinum 8175 at 3.1 GHz, and AWS introduced it in July 2018. AWS has since shipped r6i, r7i, r8i and r9g; r6i.12xlarge is the direct replacement at this size, scoring 845,256 CoreMark/s against this instance's 685,714 — roughly 23% more throughput for the same vCPU count. The closest Spot shape is mh.vs1.2xlarge at 16 vCPU, so this instance maps to 3 of them — 48 vCPU and 384 GiB across the fleet, $3.46/hr on AWS in US East (N. Virginia), from $0.063/hr on Rackspace Spot. Spot delivers compute as managed Kubernetes, so a node pool of that size is the native shape of the answer rather than a workaround — provided the workload scales horizontally.
| Region | AWS on-demand | AWS Spot | 1-yr Reserved | 3-yr Reserved | Rackspace Spot | You save |
|---|---|---|---|---|---|---|
| US East, N. Virginia | $3.456 | $0.946 | $2.177 | $1.493 | $0.063 | $3.393 savings |
| US Central, Chicago | no AWS region | $0.063 | ||||
| US Central, Dallas | no AWS region | $0.393 | ||||
| Hong Kong | $4.200 | $2.646 | $1.814 | $0.063 | $4.137 savings | |
| Sydney, Australia | $4.176 | $1.269 | $2.631 | $1.804 | $0.063 | $4.113 savings |
| London, UK | $4.056 | $1.081 | $2.555 | $1.752 | $0.393 | $3.663 savings |
| US West, San Jose | $3.888 | $1.013 | $2.449 | $1.680 | $0.006 | $3.882 savings |
| US Central, Dallas 2 | no AWS region | $0.726 |