The compute behind Microsoft Fabric, sized in capacity units (CUs). Microsoft recommends F SKUs, purchased via Azure with per-second billing.
Read more: Microsoft Learn
In the Ultra Transcenders books
Each book explains Fabric capacity in context, with comparison tables and the common traps.
Terms in this definition
- Microsoft Fabric
Analytics platform from Microsoft delivered as SaaS on top of OneLake, offering capabilities including Direct Lake and shortcuts.
- Capacity
A reserved block of compute for a tenant whose size is fixed by its SKU; Fabric F SKUs express it in capacity units (CUs). Workspaces assigned to it unlock features like Copilot, and from F64 upwards people with free licences can view Power BI content.
Related terms
- Autoscale Billing for Spark
An opt-in way of paying for Spark (Learn also calls it on-demand billing) where jobs use separate serverless compute rather than drawing on the Fabric capacity, and you pay only while jobs are active, capped by a maximum CU setting. Smoothing and bursting play no part, and at the cap new batch jobs wait in a queue while interactive ones are throttled.
- Background operation
Refreshes, scheduled jobs and most warehouse work fall into this Fabric capacity category, and their compute usage is smoothed across a full 24 hours. Interactive work, report queries for example, is smoothed over a much shorter 5 to 64 minutes.
- Burndown
The Fabric capacity mechanism whereby spare CUs in later timepoints repay carryforward, the overage that went past the 10-minute window. Throttling stays in place until the carryforward has been fully paid off.
- Capacity administrator
Assigned when a Fabric capacity is created, this role applies to that one capacity only. Its holders can alter settings, attach workspaces, add contributors and override any tenant settings delegated to the capacity; it is not the same as the Fabric administrator role.
- Capacity Overview Events
Real-Time hub events emitted by a Fabric capacity. Twice a minute a Summary event reports smoothed CU use and how much throttling is happening, and a State event fires on pausing, resuming or overload; Activator can alert on them, or an eventhouse can keep them as history.
- Carryforward
When a Fabric capacity's overage goes beyond the 10-minute throttling window, the excess is pushed into future timepoints and gradually repaid from unused capacity (burndown); throttling lasts until it's gone.
- Copilot in Fabric
Built on Azure OpenAI, this AI assistant in Power BI and Fabric takes plain-language prompts and produces KQL, SQL or DAX code, summaries and visuals. Whatever it does is charged against Fabric capacity CUs.
- Dynamic per recipient subscription
A way of emailing a report on Premium or Fabric capacity so that each of up to 1,000 people gets their own filtered version. A separate semantic model supplies the mapping from email address to filter values.