Column count :

parent 7 columns ( including 4 hidden )

type 1  8 columns ( including 3 hidden)

type 2  6 column  ( incl 4 hidden )

type 3  7 columns ( including 3 hidden )

Initialbinddepth set to 1 so everything get rendered upfront, so far this is only way page became operational...  ,

Are there any other ways to reduce view state  size.. or anything else can be done to speed it up..

Attached is source view of the page, may be something is there that I did not noticed...., do this controls can operate without writing into viewstate ?  Anyway, do you have any approach to reduce size of the rendered page ?

Data get stored in the session : retrieved once and maintained there until saved... the big grid on the first tab also some filtering capabilities implemented, the rest seems like minor addition, here is the binding on the page load and the mark up page attached:

if (IsPostBack)
            {
                if ((ExhibitLR2MasterDS)Session["ExhLR2MasterDS"] != null)
                {
                  //  ExceptionUtility.LogException("Due~~PageLoad PostBack, Data exists: " + DateTime.Now.ToString("MM/dd/yyyy hh:mm:ss.fff tt"));
                    ExhibitLR2MasterDS MasterDS = (ExhibitLR2MasterDS)Session["ExhLR2MasterDS"];
                    ExhibitLR2MasterDS.ExhLR2MasterTblDataTable MstTbl = MasterDS.ExhLR2MasterTbl;

                    uc_top_refresh.wddTopAcctFilters.AutoPostBackFlags.ValueChanged = Infragistics.Web.UI.AutoPostBackFlag.On;
                    string filter = uc_top_refresh.wddTopAcctFilters.SelectedValue;
                   
                    if (hdnAccountFilterVal.Value != filter)
                    {
                        hdnAccountFilterVal.Value = filter;
                        whdg.GridView.ClearDataSource();
                        whdg.GridView.Rows.Clear();
                        MstTbl.DefaultView.RowFilter = filter;
                        whdg.DataSource = MasterDS;   // (ExhibitLR2MasterDS)Session["ExhLR2MasterDS"];
                        whdg.DataBind();
                        whdg.GridView.RequestFullAsyncRender();
                    }
                    else
                    {
                        MstTbl.DefaultView.RowFilter = hdnAccountFilterVal.Value;
                        whdg.DataSource = MasterDS; // (ExhibitLR2MasterDS)Session["ExhLR2MasterDS"];
                        whdg.DataBind();
                    }

                    ExhibitLR2DetalsDS ExhLR2DetailsDS = (ExhibitLR2DetalsDS)Session["ExhLR2DetailsDS"];
                    wdgSrv.DataSource = ExhLR2DetailsDS.SurveyTbl;
                    wdgSrv.DataBind();
                    // SynchronizedExtra();
                    //BindExtra();                  
                }

Sorry for mistake, attached markup file,  EnabledDataViewState set to default value : False  

While trying to avoid premature optimization scenarios I'm trying to find a culprit... I do not believe that it is network, running browser on the server producing almost the same results....  as for other controls - page has some but it's just another grid with really small data set and drop downs and text boxes ( you've seen the page ), what I'll do when chance is create page with just this grid and see how it perform...  we can close this thread for now but rather get back to it when page with single grid results will be available .

I still did not have a chance to get back to this part of the project... Here I would like to know a bit more about paging :

Say I have 1500 child records about 100 per child grid.  Say I page by 10 records every child grid.  So the child grid will be bind to 100 records, only 10 displayed at once, when I click next then 10 other records displayed ... is that 10 records choose when grid gets bound... so 90 records not getting rendered to the browser and only 10 do...

If ajax is enabled so only partial update happen and if it is only 10 records why it does take so long ( about 8 sec ) ?