Amazon EC2 names explained
Instance families come in six different groups :
- General Purpose
- Compute
- Memory
- Accelerated
- Storage
- HPC
General Purpose
General purpose instances keep a balance between vCPU, memory, and network performance. Some instances add aditional capabilities to CPU (z) and network (n) and there are multiple CPU options for AMD (a), Intel (i), or graviton (g) chips.
The general purpose group includes: A, M, Mac, T
Compute Optimized
Compute optimized only includes the c type instance with different generations, capabilitities, and sizes. Almost every c instance has a 2:1 ration of memory to vCPU. If you use a medium instance with 1 vCPU it will have 2 GiB of memory. If you use a 32xlarge with 128 vCPUs it will have 256 GiB of memory.
These instances are ideal if your workloads need a lot of CPU power and not as much memory.
Memory Optimized
Memory optimized instances are for workloads that consume more memory than CPU. They have a memory to vCPU ratio ranging from 4:1 up to 32:1. An instance like r6i.xlarge has 4 vCPUs and 32 GiB of memory while an x2iedn.2xlarge has 256 GiB of memory with 8 vCPUs.
Memory optimized are some of the best instances for clusters like Kubernetes because many workloads are memory bound more than CPU bound. This will let you pack an instance with more workloads than types with lower memory to vCPU ratios.
Accelerated Computing
Accelerated computing is the most specialized of all of the groups. If you need specialized compute acceleration for your workloads you probably already know.
Most of these instance types have GPU accelerators or specialized machine learning chips. The only non-machine learning special accelerators are the f1 instances with field programmable gate arrays (FPGAs) and vt1 with Xilinx U30 media accelerator cards.
All of the types have a variety of local storage and high memory. The GPU typesโg and pโhave multiple video cards options with varying sizes of GPU memory. Some instances have multiple accelerators but not all accelerators can be shared with workloads at the same time.
Itโs more important to chose the appropriate size for these instances to optimize your usage and keep your costs low.
The accelerated computing group includes: DL, F, G, Inf, P, Trn
Storage Optimized
Storage optimized is exactly what you might thinkโlots of throughput at low latency. All of these instances will have local storage of various sizes. For most of the instances the memory to vCPU ratio is either 4:1 or 8:1.
All that disk IO wouldnโt be very useful without good network throughput and these instances generally have more network performance at smaller instance size than any other type. They donโt have the fastest network available, but faster than many of the general purpose instance types.
HPC Optimized
This group only hase one type HPC with 2 options, the hpc6id.32xlarge or hpc6a.48xlarge. You can get a big instance with Intel (i) or AMD (a) processors with the main benefits being no hyper-threading and lots of network bandwidth.
If you want HPC instances you have a very specific need that needs either 16:1 or 8:1 memory to CPU ratio. They are only available in us-east-2 and GovCloud regions so donโt expect to use these in multi-region deployments.
Storage optimized group includes: D, H, I, Im, Is