DataGrid with ObservableCollection performance question

[Dimigergo]

I have a WCT 7.1.2 DataGrid with 8 columns, 290 rows with simple converters. The itemsSource is an ObservableCollection with MVVM x:Bind pattern. The initialization of the elements takes ~10 seconds, I think it is very slow for 290 items.

Is there any simple way that I can switch off UI refresh for every Added item to the ObservableCollection? Or how can I know that the virtualization is switched on?

The DataGrid initialization is the following:

AutoGenerateColumns="False"
HeadersVisibility="Column"
CanUserReorderColumns="False"
CanUserResizeColumns="False"
CanUserSortColumns="True"
IsReadOnly="True"
SelectionMode="Single"
SelectedItem="{x:Bind Vm.SelectedItem, Mode=TwoWay}" 
ItemsSource="{Binding Source={StaticResource CvsFormList}}"
Sorting="DgSortingHandler"
GridLinesVisibility="Vertical"

Thanks in advance!

[Dimigergo]

Any advice?

[michael-hawker]

To clarify are you adding items after you've bound the collection or is the bound collection already have all the items?

[Dimigergo]

First bound the collection, and then I have some function to filter the cllection (reload). The observable collection initialize at the constructor, because if it reinitialize multiple times, the binding will be lost.

[Dimigergo]

It is just my problem? Any further information?