Hi Ajay,
Thank you for posting query to us.
I have created a sample to test the issue and tested in Eessential Studio version 6.3.0.6. It takes only less than 2 minutes to export.
Please refer the sample:
http://www.syncfusion.com/support/user/uploads/GCExport_e8a4554a.zipCould you please have a look at the above sample, if still the issue exists please provide us a sample having the issue.
Regards,
Jisha