This is typically related to a failing HDD.
Do you happen to know the HDD's manufacturer? You can either open the device and physically look at the HDD or look at the SN of the drive in the BIOS. Download that manufacturer's HDD diags - Seatools for Seagate, DLG for WD, DFT for Hitachi, etc.
You can also just download DFT - it usually reads just about everything. Follow these instructions on how to make a bootable DFT flash drive:
There is a setting in your BIOS called something like "SATA Mode" - this is going to be set to AHCI, you'll want to change it to "IDE." Then boot into DFT, press enter at every option until you get to the main screen that shows your drive. Run a long fitness test on it and see if it passes - I'm willing to bet it won't, Samsung 5s and 7s have some pretty severe HDD issues (in my experience of fixing hundreds of them over since they released).
If you're still under warranty then you can ship it to Samsung and they will replace the drive, though that will take a few weeks. Or you can buy another and install it yourself. If you do ship it to Samsung then they will absolutely not back up your data so you will need to backup anything you can before shipping it.