Fabric Implementation Guide · Part 7 of 10

Capacity Sizing, FinOps & Cost Optimization

Master Fabric Capacity Units (CUs), 24-hour background smoothing, 5-minute interactive bursting, 12h/day PAYG auto-pause, and 1-Year Reserved Instance savings.

Target Audience: FinOps Leads, Enterprise Architects, and Fabric Administrators
Estimated Read Time: 12 min

01Capacity Sizing & Compute Smoothing Math

Fabric compute is measured in Capacity Units (CUs). Understand how Fabric smooths compute usage: 5-minute interactive queries and 24-hour background job bursts are averaged over time. This prevents short workload spikes from causing immediate capacity throttling, allowing smaller SKU sizes (e.g. F64) to handle heavy peak processing.

Implementation & Verification Checklist

  • Analyze peak concurrent interactive users vs background ETL refresh schedules
  • Track Microsoft Fabric Capacity Metrics App telemetry to identify throttling trends
  • Configure automated alerts when 24-hour smoothing utilization exceeds 85% threshold
  • Evaluate F64 SKU threshold ($5,005/mo Reserved) to unlock Free Viewer report distribution

02FinOps Cost Optimization Strategies

Maximize return on compute investment by combining 1-Year Reserved Instances (~40.5% discount over Pay-As-You-Go) with automated capacity auto-pause policies. For development or non-24x7 workloads, schedule automated 12h/day pause triggers via Azure CLI / PowerShell to cut PAYG compute costs by ~50%.

Implementation & Verification Checklist

  • Purchase 1-Year Reserved Instances for continuous 24x7 production capacities
  • Implement automated 12h/day pause/resume automation for non-production development capacities
  • Audit OneLake storage growth and move inactive historical data to cold storage tiers
  • Assign clear cost center tags to workspaces for accurate showback and chargeback