The r6a.8xlarge pairs 32 vCPU with 256 GiB of RAM, the 8.00 GiB-per-vCPU ratio that marks a memory-optimized instance. In the name, "r" stands for RAM, "6" is the generation, "a" marks AMD processors and "8xlarge" is the size within the r6a family. It runs on AMD EPYC 7R13 Processor at 3.6 GHz, and AWS introduced it in July 2022. AWS has since shipped r7a, r8a and r9g; r7a.8xlarge is the direct replacement at this size, scoring 1,076,113 CoreMark/s against this instance's 648,068 — roughly 66% more throughput for the same vCPU count. Spot's node ladder tops out below this size, so r6a.8xlarge becomes 2 × mh.vs1.2xlarge (32 vCPU, 256 GiB combined), $1.81/hr on AWS in US East (N. Virginia), from $0.042/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 | $1.814 | $0.456 | $1.200 | $0.823 | $0.042 | $1.772 savings |
| US Central, Chicago | no AWS region | $0.042 | ||||
| US Central, Dallas | no AWS region | $0.262 | ||||
| Hong Kong | $0.042 | |||||
| Sydney, Australia | $2.174 | $0.897 | $1.437 | $0.988 | $0.042 | $2.132 savings |
| London, UK | $2.131 | $0.460 | $1.413 | $0.964 | $0.262 | $1.869 savings |
| US West, San Jose | $2.016 | $0.657 | $1.334 | $0.914 | $0.004 | $2.012 savings |
| US Central, Dallas 2 | no AWS region | $0.484 |