It's performing various hardware tests before showing you the BIOS screen. And even then, it usually pauses the BIOS screen for about a second to give the user

It's performing various hardware tests before showing you the BIOS screen. And even then, it usually pauses the BIOS screen for about a second to give the user enough time to hit F12 or ESC if they want to change any settings. You could probably disable both of those if you really wanted to.