Distri: 20x faster initramfs (initrd) from scratch
For those who haven't dug that deep.initramfs is essentially a tiny Linux operating root image that Linux boots to RAM, before it goes on to boot from hard disk.You can actually configure Linux to never go onto the next step of booting from hard disk,  and run the operating system purely from RAM.  Indeed there are distros such as Tinycore Linux that are designed exactly this way which can make things very fast compact and secure and diskless.