There are some folks who are interested in some actual performance numbers.
What bit rate(s), how many concurrent streams, transcoding specifics (video & audio), CPU load
@âMi Keyâ said:
I have a DS918+ and it works great (8GB ram, 3 x ironwolf, 2 x SSD cache). Last night I had 3 concurrent streams going to various clients.
Transcoding is marked as throttled (Good) and looks like each user has 8minutes of transcoded data buffered.
CPU doesnât get over loaded and I am indexing my entirely library at the same time in to plex.Plex is installed within DSM through manual packages (download from Plex) and the rest of the apps I use are in docker (such as Plexpy)
Let me know if you want me to perform any tests.
PS anyone know how to update this package? Do I stop the plex service, then simply apply the new package through the DSM interface? Does it overwrite the old package? or what should I expect?
To update PMS,
Stop PMS
Install the Update right on top of it. (it will not harm your metadata)
Start PMS
@ChuckPA said:
To update PMS,Stop PMS
Install the Update right on top of it. (it will not harm your metadata)
Start PMS
Thanks Chuck, that did the trick!
Not sure if these metrics help.
Wow?! That is much better than I expected it to perform. How is browsing the library through the client? Does everything update and display rather quickly? Also, do you happen to have an M.2 installed as a cache and know if Plex (Synology) is utilizing it at all?
@The-Dave said:
Wow?! That is much better than I expected it to perform. How is browsing the library through the client? Does everything update and display rather quickly? Also, do you happen to have an M.2 installed as a cache and know if Plex (Synology) is utilizing it at all?
I have 2 x Samsung evo 960 250GB in Read/Write mode.
I have turned off sequential IO buffering.
From what I can see the library loads instantly and I believe the majority of plex database/images are sitting in the SSD cache.
From what I can tell transcoding is stored here also as that wouldnât necessarily constitute sequential writing. Most of the transcoding users constantly show throttled which is fantastic.
Iâll monitor it when I have it loaded up with users again tonight but I could see the ssd cache hit reach 100% every 10 or so seconds by looking at the GUI in DSM. If you have any commands for me to run to gather more in-depth metrics happy to do so.
wow i also didnât expect that kinda performance from the DS918+ either which looks promising when used with the SSD cache :o
looking forward to more on this to see how it performs again as looks fantastic so far for with what it is doing, was looking also at the DS418Play, but think i may just have chuck the extra ÂŁ100 and get the DS918 from what seeing here performance wise :o
do you know for download station if it also uses the SSD cache as well? since be great for downloads, as currently use a 256gb usb drive for my nas as its TEMP storage of downloads so the hard drives isnât being trashed away 
Remember that SSDs have a limited number of bytes which can be written to them. The Samsung 850 EVO has a 150 TB maximum. If being used constantly for temporary downloads or anything else constantly being writtten, it will get âburned throughâ quickly.
I have âburned throughâ 5TB of my 1TB SSD in a month.
@ChuckPA said:
Remember that SSDs have a limited number of bytes which can be written to them. The Samsung 850 EVO has a 150 TB maximum. If being used constantly for temporary downloads or anything else constantly being writtten, it will get âburned throughâ quickly.I have âburned throughâ 5TB of my 1TB SSD in a month.
oh wow didnât look at it like that either, as i guessing as the DS918+ is using 2xNVME that it wont be as easy to just replace both of them by a simple swap since there be files still stored on them⊠which i guess even when â â â â down i guessing or is there a way to flush whats in the cache so can safely swap them when that problem occurs?
looks like on the âtry outâ list is gonna be the DS418Play then and just use the current 256gb usb stick plugged in for the âtempâ storage for download station which currently use on a little DS116 
If youâre using it as a cache for the main volume, itâs different than using it for actual temp downloads , etc.
If you have it as a stand up volume itself⊠you WILL loose data when it starts to go.
NVME SSDs arenât cheap⊠yet 
@ChuckPA said:
If youâre using it as a cache for the main volume, itâs different than using it for actual temp downloads , etc.If you have it as a stand up volume itself⊠you WILL loose data when it starts to go.
NVME SSDs arenât cheap⊠yet
ahh i see, so really for just myself as a home user it really is pointless when just using it for plex
also dont like idea if it starts to degrade heavy what happens then will it warn you? as would hate for it to fail and the messed up cache ends up ruining the whole set of files across the hddâs
true NVME isnât cheap quite yet, but is slowly coming down in price⊠but meh think just to much maybe even a overkill for what it does lol
On my DS916+ it runs about 10-12% CPU per stream if I trans-code a 1080p h264 movie to 720p or something else. I have no issue running 4 trans-codes at once. I could run more probably but other tasks still require a bit of CPU.
Only issue is the notable blocking / quality issue due to the Intel driver bugs which will hopefully be fixed in the future.
@âMi Keyâ said:
I have a DS918+ and it works great (8GB ram, 3 x ironwolf, 2 x SSD cache). Last night I had 3 concurrent streams going to various clients.
Hi - thanks to everyone who has posted such helpful info in this thread.
Having just received my DS918+ I have a couple of questions about the SSD caches. Firstly, is there an advantage in having 2 SSDs instead of just 1? Or more specifically, is there an improvement in the throughput speed when using two in parallel that goes beyond just having a larger cache?
And secondly, are there any settings in the Synology software or Plex that I should be aware of to optimise the use of the SSDs for Plex and other applications? Or does it all happen automatically?
Thanks in advance!
Iâm wondering what the speed (if any) difference is with the QuickSync engine between the DS918+ and the DS418play. Does anyone know the GPU differences? If virtualization is not a priority, for almost $200 less we could have the same streaming potential possibly.
Thoughts?
There will be no difference.
They have the same GPU
https://www.synology.com/en-us/knowledgebase/DSM/tutorial/General/What_kind_of_CPU_does_my_NAS_have
@ChuckPA said:
There will be no difference.They have the same GPU
What kind of CPU does my Synology NAS have? - Synology Knowledge Center
Thanks for the link. Yup, per Intel same exact GPU and frequencyâŠsame chip probably. It looks like the DS418play is just likely using a 4 core chip that had 2 cores fused off or something.
Well, if cache is not needed nor is virtualization, then the DS418play is one hell of a NAS for the money! Having said thatâŠI canât turn down that M.2 read/write cache option and a low power virtualized container could be nice to have 
I just started testing hardware transcoding on my Synology 918+ (8GB) running PMS 1.9.4.4325 with my Android TV as playback device. I tried some 1080p mkv files extracted from Bluray for which the hardware transcoding at different resolutions and bitrates does an excellent job as long as subtitles are deactivated. When I use PGS-subtitles, the playback stucks about every 10-20 seconds for just a second. SRT-subtitles are working fine. Using software transcoding and PGS-subtitles is also doing fine - of course with a much higher cpu load.
Has anybody else tried hardware transcoding in combination with PGS-subtitles?
well after gone for a nuc setup now for the extra power thanks to advice from @ChuckPA i was originally gonna get the DS418Play 
i went cancel my order but seems to late and been dispatched so gonna have a mess around with it and see how it performs, as be good to see how far behind the DS918+ it is for using with plex in general 
@jaywerrett said:
as be good to see how far behind the DS918+ it is for using with plex in general
Iâm very interested in hearing how this goes. As I too still canât decide on the DS418play or DS918+.
@jcwacky said:
@jaywerrett said:
as be good to see how far behind the DS918+ it is for using with plex in generalIâm very interested in hearing how this goes. As I too still canât decide on the DS418play or DS918+.
well this what i mean, for me i just needed one for plex only and maybe odd file share or backup which where i cant see the DS918+ being any better for me in this side of things unless was using it all day long over a network of users
but as want it just for plex, i will need to use some 4k test / sample files etc really so least makes it bit fairer between the DS418Play and the DS918+ if i test them out with someone with a DS918+
otherwise wont be fair using with different 4k bitrate files and profiles etc
@ChuckPA do you know any sites where can grab some 4k test files of h254/h256 etc in 8bit or 10bit etc etc 
