Are running sessions using a MySQL handler faster?

Good afternoon! Quick performance question - I'm currently preparing the release of a new website running on a Linux box written in PHP and MySQL with sessions throughout. I've read a bit about changing the PHP session handler to use a database vs. the flat file method. Does anyone have experience doing this? Are there noticeable benefits of making this change? I realize that my /tmp folder will become quite cluttered with session files, but hey - it's tmp so who cares! :) My concern comes in with overall performance of the server - if one method is better than the other. Thanks for your feedback! JT