sql - inserting 1 million records with sequence and select max -

i tried insert 1 million rows in test table using sequence , using query (using select max) posted below. surprisingly, query with select max created 1 million rows in 11:11 (11 mins 11 secs)

and query sequence create 1 million rows in 19:34 (19 mins 11 secs). not sure good

table : sitepage

create table [dbo].[sitepage](     [pageid] [bigint] not null,     [pagename] [nchar](50) not null,  constraint [pk_sitepage] primary key clustered  (     [pageid] asc )with (pad_index = off, statistics_norecompute = off, ignore_dup_key = off, allow_row_locks = on, allow_page_locks = on) on [primary] ) on [primary] 

here queries

1. query create sequence

   create sequence pagetablesequence start 1 increment 1 no cycle no cache ; 

2. query create 1 million records using select max(id)

   declare @intflag int set @intflag = 0 declare @maxrecords bigint set @maxrecords = 0 while(@maxrecords<1000000)  begin while (@intflag =0) begin   begin try   insert sitepage (pageid, pagename) values ((select max(pageid)+1  sitepage),'some page name');   set @intflag = @@rowcount    end try   begin catch   set @intflag=0   end catch  end set @maxrecords = @maxrecords+1 set @intflag=0 end  go 

3. query using sequence insert 1 million records

   declare @maxrecords bigint set @maxrecords = 0      while(@maxrecords<1000000)      begin          insert sitepage (pageid, pagename) values (next value pagetablesequence, 'some page name');    set @maxrecords = @maxrecords+1  end  go 

why there such difference in sequence , select max

try not using "no cache", use "cache 100", or 1000 instead. should give reduce io , improve performance. see http://msdn.microsoft.com/en-us/library/ff878091.aspx