Visual Studio Performance problems when writing XAML
Some tips from Disable the XAML designer in Visual Studio :
Default to full XAML view
In the Tools –> Options menu, open the Text Editor node, then the XAML node, then select the Miscellaneous node; make sure that under the Default View heading there is a checkbox beside "Always open documents in full XAML view".Kill the designer rendering process
Open the Task Manager, right-click on XDesProc.exe, and select End Process.Open as source code
Right-click on any .xaml file in your solution explorer and select "Open With…", pick the "Souce Code (Text) Editor" and click "Set as Default..".
Other tips from XAML Editor Extraordinarily Slow :
Delete the Solution User Options (.suo) file
This file is usually located in the same folder as the solution (.sln) file (better keep a backup of it).Delete the "Licenses.Licx" file
This file is found in the Project Properties folder (better keep a backup).
The article Responsive XAML editing with ReSharper shows how to turn off IntelliSense and use a ReSharper plugin instead.
The article
Visual Studio Silverlight XAML designer very slow
recommends deleting the Microsoft.ServiceModel.DomainServices.WindowsAzure.dll
assembly.
I have also seen recommendations to use the Blend XAML designer/editor instead of that of VS.