Does running a SQL Server 2005 database in compatibility level 80 have a negative impact on performance?

Question

Our software must be able to run on SQL Server 2000 and 2005. To simplify development, we\'re running our SQL Server 2005 databases in compatibility level 80. However, dat

Answer 1

after you moved the DBs over to 2005 did you

update the stats with full scan? rebuilt the indexes?

first try that and then check performance again