See if this blog on "Handy Hardware Accessment Tools" will give you the answer you're looking for as far as tools are concerned.
http://sqlserverperformance.wordpress.com/2010/11/15/handy-hardware-assessment-tools-for-sql-server/[/url]
Or you can read this thread that discusses using sqlio to measure your disk I/O.
http://qa.sqlservercentral.com/Forums/Topic634266-146-1.aspx
Hope this helps.