Quick context : I currently run Plex from a dell t20 (Xeon e3) with perfectly adequate transcoding abilities. I also have a recently got a 918+ Initially as a file server and realized it’s Plex abilities are pretty interesting.
I am now looking at shutting down the t20 most of the time and rely on the 918 even for video.
In the process of reinstalling completely the 918+, I have a few interrogations and could benefit from other users experience :
1 - what is the influence of adding read / write / both NVME drives to the DS918+ for Plex usage?
2 - what if I was to use 3 drives for data and one SSD for applications that will handle the Plex library? Would that I;prove the overall experience or also transcoding?
My guess is that the SSD usage for Plex will only significantly improve the page displays but not playing/transcoding ? Same for the NVNE read cache, with maybe a slight influence of the read cache for transcoding?
Thanks to help me decide on the disk strategy if you have experience zith the above…
H
DSM is the controlling element on how cache is used.
If you made the SSD a standalone volume and instructed the installer to install PMS on that volume, you would see maximum benefit from the SSD in the form of database response, poster displaying, and metadata because all your PMS metadata will be stored there (the Plex share).
The SSD cache only benefits after DSM has read the files from the disk and modified them.
DSM can deliver a few hundred MB/sec Read or Write which is more than enough for any video operations.
Question: Are you sure it’s NVME or is it SATA? I thought Synology only supports SATA-3 SSD. If indeed SATA-3, you’re still getting 500+ MB/sec read (based on Samsung SSD) with zero latency.
VERY nice. I was unaware it had that now. If Synology says NVME is supported go for it. Thank you for updating me. (Hard to keep track of all the changes)
I would, based on my experience with SSD cache versus SSD volume, try the SSD volume first. You can always wipe it and spin back to cache easily enough.
I think (I need to explore in details) that the M2 slots are intended by Synology to handle cache only. At least it is the way the market this : one for read and the other for write cache.
The idea is good but I don’t believe those slots can be used to create standard volumes, that would be convenient to accommodate the Plex library.
I’ll do some tests but those M2 drives don’t come cheap :neutral: !!!
As one last piece of information for you in your research & exploration:
I have M.2 volumes on QNAP (TVS-1282) and my Syno DS1815+ predates M.2 capability.
QNAP permits creation of volumes on them to the extent that QTS and its apps are installed on the M.2 (equivalent of /volume1) and my primary array bumped to /volume2. I have a 1TB Samsung 850 EVO SSD. This holds QTS, all the apps including PMS, and 8 full VMs (disk images) for support. With everything I have installed on it, I am utilizing 250 GB of its 1TB capacity. This should help you size the size SSD you need.
DSM utilizes about 4 GB of an SSD for itself and applications. PMS can be installed on any volume you designate (you’ll see this in Package Center when you install it). A huge PMS metadata library is 50GB.
This would support the idea a 250GB SSD is adequate. Referencing Amazon as a possible vendor for this: Samsung 960 EVO Series - 250GB PCIe NVMe - M.2 Internal SSD (MZ-V6E250BW) is listed at $128 USD. Samsung 960 PRO Series - 512GB PCIe NVMe - M.2 Internal SSD (MZ-V6P512BW) is listed at $309 USD
I use: Samsung 850 EVO - 1TB - M.2 SATA III Internal SSD (MZ-N5E1T0BW) which lists at $338 USD
I personally do not see the justification of 2000 MB/sec vs 500 MB/sec especially when the DS918+ CPU is a Celeron J3455 but that is your decision.
The disks on the Syno can produce 600 MB/sec peak read speed and technically the 850 EVO SSDs are slower (500 MB/sec). It is my observation and experience the gain of ‘zero latency’ far outweighs that loss in peak speed. The SSD can sustain 500 MB/sec. The HDs peak is 600MB and their sustained is closer to 300.
Just wondering if you have taken the leap to get the NVME drives for the 918+, as I am looking at upgrading my old 412+ and thought that the use of the NVME’s would be of actual real world benefit.
Hi, I’m currently utilizing a DS918+ w/ 2x 512GB M.2 NVME in R/W cache config for various types of cache testing.
(Fun tip: Compatible M.2’s can be found at a steep discount when found used/like new, pulled from parted out laptops.)
As ChuckPA mentioned, DSM + metadata can use a decent amount of storage in large libraries, so I would assume read access to those elements could improve GUI speed if they copy over to cache.
The cache also has a chance of improving performance if you have multiple users or access points streaming/transcoding the same content repeatedly over time and or concurrently. (ex. New season of [insert popular media] would get bumped into cache after a couple viewings and could take a load off the main RAID when streaming to multiple locations)
I will try to find time to run some tests with/without a cache enabled while simulating some heavy transcoding/streaming in order to determine if the difference is noticeable.
For those that haven’t taken the plunge to the DS918+, just a heads-up that you can’t use the NVMe as normal storage, only cache which you don’t have control over what files are there (DSM dynamically determines this as you access files). You may consider the Qnap TS453Be, which is somewhat more expensive if you buy the NVMe accessory card (QM2-2P), but has the same processor and RAM options as the DS918+ and Qnap allows you to use the NVMe as regular storage. Also, and they have structured tiered storage options as well.
2x Samsung 860 EVO M.2 RAID (which QTS will gladly setup for you automatically) yields a wonderful 900+ MB/sec
[~] # dd if=/dev/mapper/cachedev1 of=/dev/null bs=1M count=50000
50000+0 records in
50000+0 records out
52428800000 bytes (48.8GB) copied, 47.397052 seconds, 1.0GB/s
[~] #
This is where all applications (PMS included) are stored. The OS (QTS) kernel is in firmware (flash). When it boots, it mounts this mirror volume. Normal mirror RAID operation is striped read.
Synology does not provide this capability in any form. Synology also requires two SSDs to give you write cache. QTS allows R/W cache on one
Reviving this month-old post to revisit this, sorry for the old ping. I’m considering the 918+ or the TS453Be (or similar). Mostly for media storage, SMB, and Plex (qsv accelerated). From the tone of your post, you sound like you’d prefer the QNAP over the Synology. Am I reading that right?
Also, based on your experience with it, is there a “sweet spot” for the size/number of the NVMe SSD’s you’d get for it?
I’d like to know about this too. I’m torn between the 918+ and the TS-453Be. The TS453Be appears to be more appealing due to the fact shares can be setup on the M2 drives?
How much of a benefit is there setting up Plex on one of the M2 drives (453Be), as opposed to having them setup as a R/W cache (918+)?
@ChuckPa, what raid do you have your 860 M2 drives setup with? Raid 0 Striped?
Yes you are correctly understanding my preference:
I can create a single-SSD volume for storage, Synology doesn’t allow this
I can create a single-SSD cache, Synology only allows read-only.
I have two Samsung 860 EVO 1TB as my QTS main volume (where all apps reside)
They’re configured as RAID 1 (mirror)
This gives me 960 MB/sec read because it stripes but, as mirror, 480 MB/sec (SATA-3 interface) writing
If I pull / lose one, I’ve not lost the volume. This is nice with SSDs. When one wears out, simply pull it and pop in a new one
I took one of my 2.5" SSD slots and dropped in a 500 GB 860 there.
QNAP let me create that as a normal storage volume
I installed PMS on it. The executables and metadata are there. There’s zero latency and the only drive rattle is during maintenance , scanning, or media playback
One of the changes everyone will be seeing shortly with PMS on QNAP, which everyone already has on Synology, is the ability to select the installation volume.
In addition to volume selection, QNAP supports migration to a different volume post installation. I am currently alpha/beta testing this new installer for QNAP in the ARMv8 forum.
In addition to the new capability (a long time coming), the race condition which would make PMS show as an App Center “not enabled” error) is fixed. No more of that junk. It’s all gone.
In the sense of ‘how long to migrate’. I have about 11 GB of PMS metadata. It takes about 2 1/2 minutes to migrate to/from SSD <-> 8x 8TB WD Red Pro.
That’s a huge help, thank you. It seems clear that QNAP is the best option. I think I have two(ish) remaining questions.
I install only a few apps beyond Plex. Is anything more than 2GB RAM really necessary? I might upgrade RAM in the future if I start using Virtualization Station. If I did, have you tried third-party RAM, or do you stick with QNAP’s preferred memory?
You clearly have experience with these. I haven’t built a QNAP in a handful of years. Any recommended best practices? Based on the migration you did, I’m guessing I can add the NVMe’s later? Or better to have them installed during the initial configuration?
(Thanks for being available, especially on a weekend. This has made my research process so much easier, and I’m buying one next week.)
2x Samsung 850 EVO 2.5" 500 GB (PMS and other development)
1x 2.5" WD Black 1TB for high volume R/W (compiling, etc)
QNAP USB 3.1 option card (dual port 3.1 / 3.0)
Now for the real fun part:
HPE-1820-24G with all 4 gigabit ethernet to it LACP. (that’s 468 MB/sec capability)
Netgate w/ pfSense as PPPoE interface/router/firewall
How I use it all:
I have a VM for every Linux distro
I have my development environments all setup as well.
I can run PMS + 6 VMs concurrently without much difficulty. I only see impact when two of them are beating the CPU senseless. ( I run them in passthrough mode)
The spinner is also for all my media processing when I import the discs I rip (they take a lot of time) plus i do a raw rip of the disk. (I keep ALL the bits)
I see no reason to try and outdo what QNAP does with the RAM. The 4 DIMMS it comes with are already a matched set
Just buy it upfront. If you run Plex, you need at least 4GB. There’s a hardware transcoding sweet spot for the ASIC (no technical reason why but lots of empirical data that it is, even on the Apollolake CPUs) which shows 8GB to be the number. The J3355/J3455 (Apollolake) max at 8GB but that’s fine. It’s enough and if you’re running VirtualStation, you’ll want 16+ GB anyway.
Even now, I wish i bought the 64 GB model. (remember, I have a full “workstation in a box”)
I also wish I had waited 6 weeks. I’d have gotten the i7-7700 instead of the i7-6700 (Kabylake versus my Skylake). When the warranty has expired, I’ll get the heat sink compound kit and and the biggest rock which is pin-for-pin compatible with the 6700 and qnap has support for at the time.
