The r7i.16xlarge pairs 64 vCPU with 512 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 "16xlarge" 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.16xlarge is the direct replacement at this size, scoring 1,615,754 CoreMark/s against this instance's 1,431,874 — roughly 13% more throughput for the same vCPU count. Spot's node ladder tops out below this size, so r7i.16xlarge becomes 4 × mh.vs1.2xlarge (64 vCPU, 512 GiB combined), $4.23/hr on AWS in US East (N. Virginia), from $0.084/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 | $4.234 | $1.259 | $2.800 | $1.920 | $0.084 | $4.150 savings |
| US Central, Chicago | no AWS region | $0.084 | ||||
| US Central, Dallas | no AWS region | $0.524 | ||||
| Hong Kong | $0.084 | |||||
| Sydney, Australia | $5.074 | $2.199 | $3.353 | $2.305 | $0.084 | $4.990 savings |
| London, UK | $4.973 | $1.542 | $3.297 | $2.248 | $0.524 | $4.449 savings |
| US West, San Jose | $4.704 | $0.829 | $3.112 | $2.134 | $0.008 | $4.696 savings |
| US Central, Dallas 2 | no AWS region | $0.968 |