# In-Memory Mode | WPF Controls | DevExpress Documentation

Pivot Grid loads data and processes it on the workstation. You can select the data processing engine ([PivotGridControl.DataProcessingEngine](/WPF/DevExpress.Xpf.PivotGrid.PivotGridControl.DataProcessingEngine) ) that Pivot Grid uses in this mode: Optimized, Legacy, or LegacyOptimized.

Topics in this section describe how to populate Pivot Grid fields with data when the Pivot Grid uses In-Memory mode.

**Optimized Mode**

- [Bind Pivot Grid Fields to Data Columns](/WPF/401387/controls-and-libraries/pivot-grid/binding-to-data/in-memory-mode/Optimized-Mode/bind-pivot-grid-fields-to-data-columns)
- [Bind Pivot Grid Fields to Calculated Expressions](/WPF/8025/controls-and-libraries/pivot-grid/binding-to-data/in-memory-mode/Optimized-Mode/bind-pivot-grid-fields-to-calculated-expressions)
- [Bind Pivot Grid Fields to Window Calculations](/WPF/403913/controls-and-libraries/pivot-grid/binding-to-data/in-memory-mode/Optimized-Mode/bind-pivot-grid-fields-to-window-calculations)

**Legacy and LegacyOptimized**

- [Populate Pivot Grid Fields with Data](/WPF/404331/controls-and-libraries/pivot-grid/binding-to-data/in-memory-mode/Legacy-and-LegacyOptimized-Modes/populate-pivot-grid-firlds-with-data)

Refer to the following topic for more information about In-Memory mode, and its requirements and limitations: [In-Memory Mode Overview](/CoreLibraries/401530/devexpress-pivot-grid-core-library/pivot-grid-modes/in-memory-mode/in-memory-mode).