Time to hibernate linearly depends on amount of RAM you have, and whether you have HDD or SSD. On my 16GB T450 (SSD) with Win10 it takes several seconds.

My Toshiba Libretto seems to have it built into the BIOS. The computer displays a full-screen animation of the Laptop dumping its system memory to disk, and after a few seconds it powers down. Its all very seamless and jank free.

I use it every day on Windows 10. It takes about 30 seconds to go to full hibernate and 30 seconds to restore. My laptop has 32GB of RAM.

I use Windows 10 Pro on Asus VivoBook 15. Hibernation takes approximately one minute.