MS SQL 2005 Sever performance

Dear Sir,
Warm Greetings

One Stored procedure output started within 2 to 3 seconds and continued upto 20 seconds. If we redirect the output to a temporary table, its getting completed by 4 to 5 seconds. Anyhow if put select * from the temporary table it is taking more thann 20 seconds. Can you give some idea, whehere is the bottle neck of the issues?

Thanking you.
Regards
C.Manoharamurugan