I would think it’s for high-speed caching or something, like for disk cache or video editing. NVMe is used for direct access to the memory from the CPU, speeding it up even further. Most likely it’s for an older system before SSDs were cheap. That also means it’s likely SLC instead of the MLC or 3D architecture we’re mainly using now. That would translate to much faster relative speed (compared to similar generations of similar storage), and very good write endurance… Again, compared to other examples of the same kind of storage from a similar generation.

There’s a lot of good reasons to use small fast drives like this.

Back in the day, I took two very fast HDDs and put them in RAID 0, and attached it to my system as my application storage. I was on windows 2000 or Windows XP at the time and I had to drop to safe mode to move the contents of the “program files” folder onto the array, and remount the RAID as the folder in question. Took my a few tries to get it right, but application listing times were very fast after that.

In the early days of SSDs, I set up a small SSD for my OS and main Windows apps, and redirected my user files to a classic hard drive, since I don’t generally need high-speed access to my music and videos and such. Windows has a faculty for this where you can redirect your user folder to another location in its entirety, so my entire local user folder was on that drive, while everything else was on the SSD. I also pointed my steam games to the HDD so I didn’t have any issues with the size of game downloads.

Now that SSDs are fairly inexpensive, I’ve rebuilt my system on all flash, so I don’t need any weird disk configurations any longer.