VLDB - Create SQL DB Snapshot And Run Granular DBCC CHECKDB Commands
I think Robert Davis answered your question in two posts:

How to manually create a database snapshot and get SQL Server to use it for CHECKDB:

http://www.sqlsoldier.com/wp/sqlserver/day1of31daysofdisasterrecoverydoesdbccautomaticallyuseexistingsnapshot

Performance comparison of CHECKTABLE commands run against database vs manually created snapshot w/ different options:

http://www.sqlsoldier.com/wp/sqlserver/day15of31daysofdisasterrecoveryrunningdbccchecktableinparalleljobs