MainWindow.xaml

<dx:ThemedWindow
    xmlns:dx="http://schemas.devexpress.com/winfx/2008/xaml/core"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:DataUpdatesExample"
        xmlns:dxg="http://schemas.devexpress.com/winfx/2008/xaml/grid"
        xmlns:dxe="http://schemas.devexpress.com/winfx/2008/xaml/editors" x:Class="ChunkAndOptSummariesExample.MainWindow"
        mc:Ignorable="d"
        Title="MainWindow" Height="700" Width="1200">
    <Window.DataContext>
        <local:ChunkAndOptSummariesViewModel/>
    </Window.DataContext>
    <Grid>
        <dxg:GridControl Name="grid" AutoGenerateColumns="None" AllowLiveDataShaping="True" OptimizeSummaryCalculation="True" ItemsSource="{Binding Devices}">
            <dxg:GridControl.TotalSummary>
                <dxg:GridSummaryItem SummaryType="Count" FieldName="Name" DisplayFormat="Total count: {0:N0}"/>
            </dxg:GridControl.TotalSummary>
            <dxg:GridControl.GroupSummary>
                <dxg:GridSummaryItem FieldName="Sensor1" SummaryType="Average"/>
                <dxg:GridSummaryItem FieldName="Sensor2" SummaryType="Sum"/>
                <dxg:GridSummaryItem FieldName="Sensor3" SummaryType="Average"/>
            </dxg:GridControl.GroupSummary>
            <dxg:GridControl.Columns>
                <dxg:GridColumn FieldName="Name"/>
                <dxg:GridColumn FieldName="Group" GroupIndex="0"/>
                <dxg:GridColumn FieldName="Sensor1"/>
                <dxg:GridColumn FieldName="Sensor2"/>
                <dxg:GridColumn FieldName="Sensor3"/>
            </dxg:GridControl.Columns>
            <dxg:GridControl.View>
                <dxg:TableView GroupSummaryDisplayMode="AlignByColumns" ShowTotalSummary="True"  />
            </dxg:GridControl.View>
        </dxg:GridControl>
    </Grid>
</dx:ThemedWindow>