Display Huge data on MSchart and Zedgraph

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C#

I am working on Winfrom application where, I am reading a text file and display its huge data to Zedgraph and MS chart. Everything is fine. Problem is appearing when I use minimize and Maximize options. I hide the form by pressing the minimize button which is on the upper right side of the window. When I click on form to display form, Its appearing white screen means form not showing graph for some period.
After two and three seconds, it comes to normal condition. I know it is coming due to huge data .But I can‘t reduce data points. Can anyone help me for this issue?

Thanks in advance!