In my Synology DiskStation DS920+ review I already touched on SSD caching and how it speeds up file transfers to NAS devices. Synology sent me a couple of their SNV3400 NVMe SSDs to pop into my Synology NAS to fully take advantage of it.
Now, as many of you are thinking. No, this is not a ploy to fix you into buying Synology drives / SSDs etc with your Synology NAS as you’re still able to use any NVMe drive in your Synology NAS but there is a problem with doing so with regular consumer-grade SSDs and that is drive wearing.
With the original Samsung 950 Pro I found in a drawer it was already in a used state so for starters I had no idea how “worn” this was. SSD’s, unlike hard drives do wear over time and my 950 Pro only has an endurance of a quoted 200TBW (terabytes written). Being a cache drive, this is not really a big deal however if data was written to a worn drive then failed this does increase the chance of data loss if a drive were to suddenly fail on a busy NAS. The Synology SSDs are able to determine and report back to the Synology NAS their life remaining based of use and alert you if a SSD cache is potentially nearing end of life.
The Synology SSD has a read speed of 3100MB/s however a slower write speed of 500MB/s compared to other NVMe SSDs but has an endurance of 500TBW meaning it is likely to last longer with busy workloads. Given the DiskStation DS920+ has 2x 1GbE Ethernet ports you’re likely not going to totally max out the writes on the SSDs regardless unless if you were running something intensive on the NAS itself.
Adding 2x NVMe drives to your NAS gives you full read / write caching - basically what happens is your data is written to the SSDs and written (over time) back to the much slower RAID giving you a performance boost whilst also helping prevent disk thrashing on busier NAS devices (like ones used in offices). The read cache basically takes common files that are read and caches them meaning reading these files doesn't touch your array.
On testing, we found that we had no problems at all working directly off the NAS with Lightroom (HDR Raw files). With some video files it is also now possible to work directly from the NAS however you do run into limitations of the network bandwidth itself with more professional video formats or larger files. It was also possible to host much more intensive things on the NAS such as a Valheim server with no issues at all.
In all, I think that spending the little extra to add the Synology NVMe drives to your NAS is a worthwhile investment given they’re designed for reliable operation for years to come.
