I don't know. I only do that once every few months on my production systems, so it's not important. If anything the bios checks are longer than the OS boot itself. Mrk
With a well-trimmed Windows 10 v.1607 and little third-party stuff, 20 sec is right on the money. Keeping C (Windows) drive on a small SSD with just 110 gigabytes is one of the more effective methods I've used.
7.9 seconds with a Samsung 850 Pro 512GB SSD on my Alienware laptop in UEFI mode with Windows 10 Enterprise x64.
I don't care about it on my home PC as well. I only do it once or twice a day, so a few seconds more or less won't make a difference. I don't care about wallpapers as well since I'm on my desktop for only about 1 minute every week.
Wow, 10 seconds and under for reboot time is amazing. Did you apply any tweaks or modifications, and did you disable any startup programs or is that with defaults set?