The r7i.12xlarge pairs 48 vCPU with 384 GiB of RAM, the 8.00 GiB-per-vCPU ratio that marks a memory-optimized instance. In the name, "r" stands for RAM, "7" is the generation, "i" marks Intel processors and "12xlarge" is the size within the r7i family. It runs on Intel Xeon Scalable (Sapphire Rapids) at 3.2 GHz, and AWS introduced it in October 2023. AWS has since shipped r8i and r9g; r8i.12xlarge is the direct replacement at this size, scoring 1,169,591 CoreMark/s against this instance's 1,058,396 — roughly 11% more throughput for the same vCPU count. Spot's node ladder tops out below this size, so r7i.12xlarge becomes 3 × mh.vs1.2xlarge (48 vCPU, 384 GiB combined), $3.18/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 | $3.175 | $1.167 | $2.100 | $1.440 | $0.063 | $3.112 savings |
| US Central, Chicago | no AWS region | $0.063 | ||||
| US Central, Dallas | no AWS region | $0.393 | ||||
| Hong Kong | $0.063 | |||||
| Sydney, Australia | $3.805 | $1.608 | $2.514 | $1.729 | $0.063 | $3.742 savings |
| London, UK | $3.730 | $1.015 | $2.473 | $1.686 | $0.393 | $3.337 savings |
| US West, San Jose | $3.528 | $0.772 | $2.334 | $1.600 | $0.006 | $3.522 savings |
| US Central, Dallas 2 | no AWS region | $0.726 |