r5d.4xlarge is AWS's memory-optimized EC2 size at 16 vCPU and 128 GiB. In the name, "r" stands for RAM, "5" is the generation, "d" marks local NVMe storage and "4xlarge" is the size within the r5d family. It runs on Intel Xeon Platinum 8175 at 3.1 GHz, and AWS introduced it in July 2018. AWS has since shipped r6i, r7i, r8i and r9g; r6i.4xlarge is the direct replacement at this size, scoring 267,525 CoreMark/s against this instance's 232,863 — roughly 15% more throughput for the same vCPU count. On Rackspace Spot the same shape is mh.vs1.2xlarge — 16 vCPU, 128 GiB, matched on both dimensions, $1.15/hr on AWS in US East (N. Virginia), from $0.021/hr on Rackspace Spot.
Match qualityNo local disk
r5d.4xlarge comes with 2 × 300 GB NVMe SSD attached to the machine. Rackspace Spot nodes use network storage only, so that disk does not come with it.
If you were using the local disk as fast scratch space — temporary files, a local cache, an index — you will need a persistent volume or object storage instead, and both are slower to read. If it was just extra space you never depended on, nothing changes.
