How fast is LINQ?

Question

I need to manipulate 100,000 - 200,000 records.
I am thinking of using LINQ (to SQL) to do this.
I know from experience that filtering dataviews is very slow.
So

Answer 1

You need to be more specific with what you mean by manipulate the records. If the changes are not 100% individual for each record and can be made set-based you are most likely better of doing the changes in T-SQL on the db side (stored procs). In other words avoid pulling large amounts of data over network and/or process boundaries if possible.