The x2gd.12xlarge pairs 48 vCPU with 768 GiB of RAM, the 16.00 GiB-per-vCPU ratio that marks a memory-optimized instance. In the name, "x" is the extra-memory line, "2" is the generation, "gd" marks AWS Graviton (ARM) processors and local NVMe storage and "12xlarge" is the size within the x2gd family. It runs on AWS Graviton2 Processor at 2.5 GHz, and AWS introduced it in March 2021. AWS has since shipped x8i; x8i.12xlarge is the direct replacement at this size, scoring 1,197,605 CoreMark/s against this instance's 952,696 — roughly 26% more throughput for the same vCPU count. Spot's node ladder tops out below this size, so x2gd.12xlarge becomes 6 × mh.vs1.2xlarge (96 vCPU, 768 GiB combined), $4.01/hr on AWS in US East (N. Virginia), from $0.126/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 | $4.008 | $1.322 | $2.470 | $1.369 | $0.126 | $3.882 savings |
| US Central, Chicago | no AWS region | $0.126 | ||||
| US Central, Dallas | no AWS region | $0.786 | ||||
| Hong Kong | $0.126 | |||||
| Sydney, Australia | $0.126 | |||||
| London, UK | $0.786 | |||||
| US West, San Jose | $0.011 | |||||
| US Central, Dallas 2 | no AWS region | $1.331 |