Hi emil_tr,
I think could try to use WPF virtualization, for more details, you could refer to:
http://bea.stollnitz.com/blog/?p=338
http://www.codeproject.com/KB/WPF/WpfDataVirtualization.aspx
http://bea.stollnitz.com/blog/?p=344
I think the virtualization could help you a lot.
If your issue persists, please let me know.
Best regards,
Sheldon _Xiao[MSFT]
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