My opinion hard disk drives are fine for back-up and archiving, get modern and go SSD
Yes, Bill's advice is good. Only have OS and programs on your "boot drive" , which should be a quality SATA III SSD, like a 500GB or larger Samsung 850Pro.
Then ALL ELSE should go on a new Samsung 950 Pro PCI SSD which runs at over 2 GB /sec read and 1.5 GB/sec write. You may need an "adapter card" in order to plug this new drive into an available PCI slot. Then, a large, spinning HDD can be used to backup and archive completed files and valuable media.
Or, you can just install two,or even three quality SSDs in a fast RAID 0 off the motherboard to give you a higher capacity single volume for your "media drive",or" project drive" ALL files not on the boot drive would go here for best performance and again, you would have a large, spinning HDD also installed to serve as an archive and backup drive.....preferably an "enterprise level" 7200RPM hard drive with a large capacity, at least as big as the RAID 0 volume
A RAID 0 of three Samsung 850 Pro SSDs should give at least 1.5 GB/sec. read and 950MB/sec write speed. Spinning HDDs are just too slow in comparison for use in current video editing, and are often the main cause of performance "bottlenecks". They are good for backing up and archiving.