is don't bother unless the new BIOS addresses a problem you are having or adds a feature you desire. As for the best way, I prefer bootable media of any type rather that will allow you to make a backup of the old BIOS version first. Make sure there's no way your PC can power down during a flash or it may be dead. This means a good working UPS. As for performance boosts, that depends. Read what's fixed or added in each revision. Some might offer support for newer processors that might be faster but, on the whole, overall system speed ups aren't part of the MB sustaining crew's objective.