Not able to see content during download of large amount of data


I've a Rhoelement application which will fetching data form a webservice; the amount of data more than 1 lakh. When I trry to login it will initially fetch more than 4k data.Secondly after login when I am going for fetching other option to get data i.e more than 1lakh it will taking too much time.

Questions is: How to resolve that issue for both the cases? how can I login  immediately then it will download data and how to handle download large amount of data after some intevals.

Though I've used Bulk-sync but it didn't solve the issue.

If anyone faced that problem please help me