Originally Posted by Slax-Dude
I'm guessing he will put the OS on an SSD and the changes overlay on an HD.
That would indeed speed things up and, since the OS is read-only, it would extend the life of the SSD.
That would likely slow things down because everything that needs to be written would no longer get written on a fast SSD, but on a slow HDD. Reads would be fast as expected (unless it is accessing something that has changed and is now on the HDD), but any writes would be quite slow. In my personal opinion, this wastes the potential of the SSD (like people who store /tmp or swap on an HDD, when those would benefit highly from the increased SSD speed).
And extending the life of the SSD is a largely pointless endeavor
on modern SSDs. They'll write more data than most users could ever imagine to write
before the NAND fails due to excessive writing (we're talking almost 5 years of writing 400GB every day to the drive -- and that's just for the first drive that failed).