GSquared (8/6/2012)
The whole idea is to maximize bandwidth that can be used to read/write in tempdb.....
Same for multiple files. It will often create zero advantage to have multiple tempdb data files, if they're all on the same disk. Why? Because it'll still have to take turns reading and writing. Hard drives read and write sequentially. They only do one thing at a time.
This information is very, very wrong.
The reason it is recommended to use multiple data files for tempdb has absolutely nothing to do with bandwidth. It is about alleviating contention on the allocation pages. for more details:
Read my tempdb whitepaper: http://www.idera.com/Action/RegisterWP.aspx?WPID=37
Watch my tempdb webcast: http://www.idera.com/Events/RegisterWC.aspx?EventID=208