EC2 Instance Performance Tiers

T, M, C, R, X families.

Overview

EC2 instance performance tiers chooses the right family for each workload. Five families (T, M, C, R, X) cover most workloads; the discipline is matching the family to the workload constraint instead of defaulting to whatever the team learned first.

• T, M, C, R, X families. Per-workload family selection; the family reflects the workload constraint.
• T: burstable, low cost. Per-burstable T-family; matches workloads with idle baseline and occasional spikes.
• M: balanced. Per-balanced M-family; the right default when CPU and memory are balanced.
• C compute-optimized plus R/X memory-optimized. C-family for CPU-bound, R/X for memory-bound; the family ratio matches the constraint.

The approach

The practical approach: per-workload family selection, T for burstable, C for CPU-bound, R/X for memory-bound, documented per-service rationale. The team’s discipline produces matched compute that runs cheaper without sacrificing performance.

• Per-workload family. Per-workload family; the choice reflects the actual workload constraint.
• T for burstable. Per-burstable T-family; the burstable model matches workloads with low average load.
• C for CPU-bound. Per-CPU-bound C-family; higher CPU-to-RAM ratio matches the constraint.
• R/X for memory-bound plus documented rationale. R/X-family for high-memory workloads; per-service family rationale committed for operational reviews.

Why this compounds

Family discipline compounds across services. Each correct family produces ongoing cost-performance; the team’s compute discipline grows; new services inherit the family-selection methodology.

• Better cost efficiency. Right family matches workload; the bill tracks workload constraint, not vendor default.
• Better performance. Right family matches workload; the workload runs at design capacity.
• Better operational fit. Right family matches team; the operational pattern stays simple when families align consistently.
• Institutional knowledge. Each decision teaches compute patterns; the team’s capacity engineering muscle grows.

Family discipline is an operational discipline that pays off across years. Nova AI Ops integrates with compute telemetry, surfaces patterns, and supports the team’s compute discipline.