Not every system can run Optane. Intel made sure of that.
Further, not everyone can afford a 2TB SSD.
Even an old Intel 80GB SSD with Primocache and a 4GB buffer takes a highly modded Fallout 4 startup time from upwards of five minutes to a little under one minute. That's not placebo.
Having the OS interface write files at 5+ GB/s and handle the rest in the background is not placebo. Having the IO increase to the capacity of RAM rather than a HDD or SSD is not placebo.
It is not a perfect solution, that would be a PCIe 4.0 NVME, but if you've got some spare parts and a little extra RAM you can *actually* get NVME speeds on files you're working on.
I'll take my DVR videos, run them through Staxrip and have the 2GB files ripped at the speed of my RAM ready for encoding in spite of the fact that they're on a mechanical hard drive.
The difference of 2 seconds vs 1 minute is not placebo.
Samsung RAPID has no user configurable options and can't cache a mechanical drive. Primocache has a ton of options, can be adjusted on the fly. When gaming I set it to 2-4GB, when doing video work I'll set it as high as 8GB and tear through the video files.
Further, I recommend reading up on the difference between AMD's accelerator and Primocache. Primocache is 100% non-destructive. You can pull the SSD without issue. AMD's acceleration, if the SSD is gone your data is gone as the files are actually moved from the drive to the SSD. As much as I like AMD they chose the wrong company to partner with for their caching option.