Amazon EC2 Instances
Instance families group hardware by the resource they favor. Pick the family whose bottleneck matches your workload; the number is the generation.
| Family | Optimized for | Choose when | Watch out |
|---|---|---|---|
| General Purpose (T3) | Balanced CPU/memory, burstable | Web servers, dev boxes, spiky low-baseline work | T-series throttles once CPU credits drain |
| Compute Optimized (C5) | High sustained CPU | Batch, HPC, transcoding, ad serving | No bursting — pay for CPU you run hot |
| Memory Optimized (R5a) | High RAM per vCPU | In-memory DBs, real-time analytics, SAP HANA | Holds data in RAM, not on disk |
| Storage Optimized (D2) | High local disk I/O | Data warehouses, distributed file systems | Instance-store data is ephemeral |
| Accelerated Computing (F1) | Hardware accelerators (FPGA/GPU) | ML, genomics, custom hardware acceleration | Only pays off if the workload uses the accelerator |
- Amazon Machine Image (AMI) is the template an instance launches from — it defines software; the family defines hardware.
- Pricing (On-Demand, Spot, Reserved, Savings Plans) is a separate axis — see Instance Pricing Options.