Why is SQL Server slower than Access/FoxPro/DBase etc.

The mentioned products are great for "small" numbers of users and"small" databases. They carry very little overhead and rely on theclient for record/file locking. This is great for one or a few number of users,or when data is read-only, but when many users access the system the overheadof doing locking by file offset with SMB packets is enormous, and theapplication will usually grind to a halt/connections will be lost/database willbe corrupted etc.
SQL Server is a true client/server app and so scales far better, but theoverhead of doing all the locking etc. at the server end is far higher in somecases.
(Note "small" is a relative term - this could be a hundred users anda 1Gb database - which is large to many people).#

SQL Server logs all writes to a transaction log before it writes to actualdata pages. It also (with 6.5 and below) has to update indices when records inthe main table are changed due to page splits etc. This overhead is great forconsistency and reliability, but not for raw performance. This logging cannotbe turned off.