The i4i.12xlarge pairs 48 vCPU with 384 GiB of RAM, the 8.00 GiB-per-vCPU ratio that marks a storage-optimized instance. In the name, "i" is I/O, meaning local storage, "4" is the generation, "i" marks Intel processors and "12xlarge" is the size within the i4i family. It runs on Intel Xeon 8375C (Ice Lake) at 3.5 GHz, and AWS introduced it in October 2023. AWS has since shipped i7i and i8g; i7i.12xlarge is the direct replacement at this size, scoring 1,053,402 CoreMark/s against this instance's 817,926 — roughly 29% more throughput for the same vCPU count. Spot's node ladder tops out below this size, so i4i.12xlarge becomes 3 × mh.vs1.2xlarge (48 vCPU, 384 GiB combined), $4.12/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.
Match qualityScale-out match
i4i.12xlarge gives you 48 vCPU and 384 GiB in a single machine. The largest comparable Spot node, mh.vs1.2xlarge, is 16 vCPU and 128 GiB, so the equivalent here is 3 nodes rather than one.
Spot runs as managed Kubernetes, so a 3-node pool is the normal way to run things rather than a workaround. If your workload already sits behind a load balancer, a queue or a scheduler, it spreads across them without changes. If it needs all 48 cores and 384 GiB in one process, it does not.
No local diski4i.12xlarge comes with 3 × 3,750 GB NVMe SSD attached to the machine. Spot nodes use network storage only, so that disk doesn't come with it. If you were using it as fast scratch space, you'd move to a persistent volume or object storage, which are slower to read.
