slow Insert-Select

i've wuold like to use this query to collect activity into a table evevry 1-2 minutesthe problem is that if i run only select it tooks less than 1 second, but when i do insert into select, the same tooks about 6 or more secondscreate view [dbo].[activity] asWITH ctethread_addrs (SPID, THREAD_ADDRESS) AS ( select B.SPID, A.thread_address from SYS.SYSPROCESSES B, SYS.DM_OS_THREADS A where b.dbid > 4 and b.program_name not like '%Microsoft%' and b.kpid = A.os_thread_id ), cteActiveSessions (log_time,session_id,text,status,cpu_time,start_time,wait_type, host_name,program_name,login_name,dbname,command,blocked_by,query_plan) AS ( SELECT GETDATE() as log_time, r.session_id, s.text, r.status, r.cpu_time, start_time, r.wait_type, se.host_name, program_name = se.program_name, se.login_name, Db_name(r.database_id) AS dbname, r.command, r.blocking_session_id AS Blocked_By, p.query_plan AS query_plan FROM sys.dm_exec_requests r WITH (NOLOCK) INNER JOIN sys.dm_exec_sessions se WITH (NOLOCK) ON r.session_id = se.session_id OUTER APPLY sys.dm_exec_sql_text(r.sql_handle) s OUTER APPLY sys.dm_exec_query_plan(r.plan_handle) p WHERE r.session_id <> @@SPID AND se.is_user_process = 1 and login_name <> 'NT AUTHORITY\SYSTEM' )SELECT ac.log_time, ta.thread_address, ac.session_id, ac.text, ac.status, ac.cpu_time, ac.start_time, ac.wait_type, ac.host_name, ac.program_name, ac.login_name, ac.dbname, ac.command, ac.blocked_by, ac.query_plan FROM cteActiveSessions AS ac INNER JOIN ctethread_addrs AS ta ON ac.session_id = ta.spid CREATE TABLE activty_log ( [log_time] [datetime] NULL, [thread_address] [bigint] null, [session_id] [int] NULL, [query] [nvarchar](max) NULL, [status] [nvarchar](30) NULL, [cpu_time] [int] NULL, [total_elapsed_time] [datetime] NULL, [wait_type] [nvarchar](50) NULL, [HOST_NAME] [nvarchar](50) NULL, [PROGRAM_NAME] [nvarchar](70) NULL, [LOGIN_NAME] [nvarchar](70) NULL, [DBNAME] [nvarchar](70) NULL, [COMMAND] [nvarchar](70) NULL, [BLOCKED_BY] [int] NULL, [query_plan] xml) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]insert into activty_logselect * from activity;the slow part is on SYS.DM_OS_THREADS, indeed if i remove it the insert runs fast as select, any ideas?thank you