Bind 7000 records in Gridview takes more time.

function BindMembersDetails()
    {
        // to call c# funstion        
       __doPostBack('<%=lnktxtsearch.ClientID %>', '');
    }

Asp.net
<asp:TextBox type="text" placeholder="Search..." class="textbox" runat="server" ID="txtSearchKey" onkeyup="BindMembersDetails()" autofocus></asp:TextBox></div> 


  <asp:GridView ID="grdMemDasboard" runat="server" class="grid grdHouseKeeping" AutoGenerateColumns="false"
                CellPadding="0" BorderColor="#cccccc" CellSpacing="0" BorderWidth="0" EmptyDataText="No Items Added"
                onsorting="grdDasboard_Sorting"
                   AllowSorting="true">
                <%--AllowPaging="true" OnPageIndexChanging="grdItemMaster_PageIndexChanging" PagerSettings-Position="Bottom" PageSize="40" --%>
                <Columns>
                    <asp:TemplateField ItemStyle-CssClass="gridCourse" HeaderStyle-CssClass="gridCourse  gridCourseHeader" HeaderText="Membership Id" Visible="false">                       
                        <ItemTemplate>
                            <asp:LinkButton runat="server" ID="lblMembershipId" Text='<%#Eval("MembershipID") %>' ></asp:LinkButton>
                        </ItemTemplate>
                    </asp:TemplateField>
                   
              etc.....

                </Columns>
            <%--    <PagerSettings FirstPageText="First" Mode="NumericFirstLast" LastPageText="Last"
                    PageButtonCount="7" NextPageText="Next" PreviousPageText="Previous" />--%>
            </asp:GridView>

// Repeater for paging 
  <asp:Repeater ID="rptPager" runat="server" >
            <ItemTemplate>
                <asp:LinkButton ID="lnkPage" runat="server" Text = '<%#Eval("Text") %>' CommandArgument = '<%# Eval("Value") %>' Enabled = '<%# Eval("Enabled") %>' OnClick = "Page_Changed"></asp:LinkButton> <%--OnClick = "Page_Changed"--%>
                <asp:HiddenField ID="hdnValue" runat="server" Value='<%# Eval("Value") %>'/>
            </ItemTemplate>
            </asp:Repeater>      
            </div>

Stored Procedure
SELECT ROW_NUMBER() OVER(ORDER BY MM.MemberID DESC) AS RowNumber,
MCM.CategoryName as MembershipName,
      --(case when ISNULL(MCM.IsCorporate,0) = 0 then MM.MemberCode  when ISNULL(MCM.IsCorporate,0) = 1 then (select t.memcode   from @temp t where t.memeberid=mm.MemberID ) end) as MemberCode --MM.MemberCode   
	  MD.MemberCode as MemberCode
	  ,MCM.CategoryID
      ,MM.MemberID  as MembershipID
      ,GU.CardName as PrimaryMember
	  ,(select Count(memberid) from Mem.MemberDetails MD where MD.MemberID=MM.MemberID) as TotalPax --case when isnull(MCM.IsCorporate,0)=0 then '' else MCM.NoOfPax end as TotalPax
	  ,case when MM.Approverflag=1 then 'Approved' when MM.Approverflag=2 then 'Rejected'  else 'Pending' end as [Approval]   
      ,[MembershipCategoryID]
      ,CONVERT(varchar(50),ExpiryDate,103) as ExpiryDate 
	  ,[SecurityDeposit]
	  ,[EntranceFee]
      ,[CorporateName]
      ,[TotalAmount]      
      ,ISNULL(md.[Balance],0.00) as Balance
	  , MCM.IsCorporate  
	  ,(case when ISNULL(MCM.IsCorporate,0) = 1 then MM.CorporateID  when ISNULL(MCM.IsCorporate,0) = 0 then '0' end) as CorporateID  --MM.MemberID
	  , MM.IsActive as IsActive
	  , MD.MemberCode as memcode
	  --,(Select Description from Mem.MemberShipStatusMaster where StatusCode=MM.StatusCode) as Status
     ,case when MM.[IsActive]=1 then 'Active' else 'In-Active' end as [Status]
	 INTO #Results
  FROM [Mem].[MemberMaster] MM 
  inner join [Mem].MembershipCategoryMaster MCM on MCM.CategoryID=MM.MembershipCategoryID
  inner join [Mem].MemberDetails MD on MD.MemberID=MM.MemberID
  inner join [dbo].Guest Gu on GU.guestID=MD.GuestID ORDER BY MD.MemberID desc 
      SELECT @RecordCount = COUNT(*)
      FROM #Results
      SELECT * FROM #Results
      WHERE RowNumber BETWEEN(@PageIndex -1) * @PageSize + 1 AND(((@PageIndex -1) * @PageSize + 1) + @PageSize) - 1
      DROP TABLE #Results