Plex Data Server Location
You can move the Plex data folder to another drive. See [HowTo] An extended guide on how to move the Plex data folder on Windows
Having the Plex data folder on an SSD vs HD will make no difference once the streaming starts. The movie/show/etc is read from where it is stored. The Plex data folder is not needed at that point.
In theory, using an SSD may make a difference in the responsiveness of Plex apps (how fast cover art and other information is displayed).
When you view available media in a library, the Plex server sends cover art for each item to the client. The cover art is stored in the Plex data folder. The faster the media where the data is stored, the faster the Plex server can send it to the client, and the faster it is displayed onscreen.
Whether or not it makes a difference for you depends on the amount of traffic on your server. If you have 5 simultaneous users it probably won’t make a difference. If you have 75 simultaneous users then it might.
I’m in the five user camp. I run Plex Media Server on a Synology DS918+ with no SSDs for caching. I’ve no problem loading cover art, etc from a library with ~900 movies.
Transcoding & SSDs
Some forum users have expressed concern that having Plex’s transcoder temp directory on an SSD will shorten the life of the SSD (When transcoding, Plex reads/writes many temp files as it converts audio/video between formats).
Search the forum for “SSD transcode” or similar terms to see the threads.
As I run PMS on a NAS with no SSDs, I cannot provide any details on SSD wear from transcoding.
SATA vs M2 SSDs
This is my experience with my home Win10 PC, which does not run Plex Media Server.
If the M2 SSD has a SATA interface, then you will not see much difference versus a 2.5" SATA SSD. The limiting factor is the 6 Gbps SATA interface.
For M2 PCIe SSDs, check the capabilities of your motherboard. On some mobos (such as mine), the M2 slot only has 2 PCIe lanes, which limits data transfer speed to ~10 Gbps. It is still faster than SATA, but if you’ve a fast SSD, you’ll still hit the limit of the interface.
For my home PC, I used a M.2 to PCIe x4 add in card. It lets me use the full capabilities of the SSD. The system is definitely more responsive than when the boot drive was a 2.5" SATA SSD.
Adding the card knocked my graphics card from x16 to x8 due to mobo limitations. I don’t game or have other heavy video usage on the PC, so there was no negative impact to my system.
