Performance issue on Inspiron 3451 after bios update

I recently updated my Inspiron 3451 bios from A00 to A05, and the update finished successfully, no errors or interruption during the update. But here is the problem, when the laptop was still in bios version A00, it load the windows quickly after i switched on the laptop, and after it updated to version A05, i have to stuck on the dell logo for about 8-10 seconds, waiting, without windows loading animation or any harddrive activity (from fn+h combination), but after that, the windows loading animation comes up and system start quickly.

i have tried everything, resetting the bios, updating the drivers and windows, and even reinstalling the windows, but still. It's truly annoying to wait for that long, although the laptop works well for daily use. Is there any workaround for this problem? i'm thinking about downgrading the bios to A00.