I currently have a DS916+ that I’ve been using HW transcode on for about the last 6-8 months. I moved to this system from a larger box that used software transcoding. While I like the compact size and reduced power usage, the quality difference between QSV and software kind of bugs me. I’m also starting to get some 4k and h.265 content, which the DS916 doesn’t always handle that well.
I’m thinking about moving to a DS918+, and I was wondering if anyone could give me their impressions on the differences between the two systems. In particular:
- Does the HD500 QSV in the DS918 have better h.264 output?
- Will the Plex HW transcode engine output h.265 to clients that support it? (My clients are recent FireTV and AppleTV boxes with h.265 HW decode.)
- If so, is the output higher quality than h.264, lower bitrate, or both?
Thanks in advance to anyone who might be able to help me!
Yes. The N3050 has a less sophisticated GPU than that of the J3455 (newer silicon / newer generation GPU)
Slight correction; the DS916+ has the Intel Pentium N3710 (Brasswell generation)
For the differences regarding features between DS916+ and the DS918+ (Apollo Lake generation), see ‘Intel Pentium and Celeron family’: https://en.wikipedia.org/wiki/Intel_HD_and_Iris_Graphics#Intel_Quick_Sync_Video
DS916+ will only decode 8bit HEVC.
DS918+ will decode and encode 8bit and 10bit HEVC (and should be fine for pretty much all 4K stuff you throw at it, but please correct me if I’m wrong).
Regarding actual differences between encoding/decoding quality; I’m not sure if there will be a difference, I’m afraid someone will have to compare both running identical tests.
Thanks for catching that. I had accidentally picked up the DS216+
Braswell versus ApolloLake is fundamental point.
The transcode silicon itself is less sophisticated (obviously)
Sorry, I somehow missed notifications of the responses here. I’ve actually got a DS918 on the way, so I guess I’ll try to test h.264 quality differences myself. If I get any worthwhile results, I’ll try to post them here.
Regarding the hardware h.265 encoding, my guess is that the current answer is: “No, plex does not currently support h.254 hw transcode.”? From stuff I’ve gathered elsewhere in the forums, it appears that 4k streams need a different container format than is currently used? Would that apply to 1080p and lower streams as well?
@ChuckPA said:
The new NAS compatibility list is now publicly available.
https://support.plex.tv/articles/201373803-nas-compatibility-list/
That’s interesting, thanks for the pointer!
I notice the HW compatibility list says “No” under 4K HW decode, and I know I’ve seen other places in the forums that Plex uses the HW decode in the new CPU. (EG Here) Several of the QNAP devices have “decode only” entries, so I was wondering if that might be a mistake in the spreadsheet?
Can I take the complete lack of 4K HW encode as an endorsement “needs a different container” explanation, or is it a lack of device support, or some other issue? Thanks!
Specific model please? I did a complete overhaul of the entire list. I’ve triple checked it but anything is possible.
Regarding “Decode Only”, Plex does not transcode to a 4K output resolution. If your TV / monitor / player is 4K capable, it should be capable of DirectPlay or, at worst, DirectStream. Video will not re-encoded to some variant of 4K
Synology DS918+’
Yeah, I understand there isn’t a 4K to 4K transcode currently. I was just wondering if h.265 encode at any resolution or 4K transcodes are on the horizon. (To the extent you’re allowed to talk about future features.)
HEVC at 1080p is fine.
4K HEVC 8-bit should be OK… Others report it can do it.
I just completed the guide and have not had time to verify the DS918+ (waiting to get one in the lab) so had to go by the raw specs.
there are other folks here who have reported success with 4K SDR (8-bit) .
This is consistent with Intel’s released info: Kaby Lake at high-end and Apollo Lake at entry level I do not know the bit rate cutoff point.
If anyone has hard data for me to review, I will gladly update the sheet.
OK. I did some testing, and 4K 8bit does decode just fine on the 918, where it’s a stuttery mess on the 916. (FWIW, the post I linked above actually appears to be you advising someone of the same thing.)
I also did some testing on the differences between HW h.264 transcode on the DS916 and DS918, my method was to “optimize” a short clip on both systems at my most common remote streaming profile (720@3Mb), then compare the resulting files. There were minor differences between the streams, but if the files were blinded, I wouldn’t be able to tell which came from which silicon.
An interesting aside is that encoding speed was noticeably different - the the DS916 averaged about 2.5x with HW transcode, while the DS918 averaged around 3.5x. Interestingly, software encoding on Very Fast was substantially faster on both systems with comparable video quality. The DS916 hit around 9.5x in software, while the DS918 was around 12x.
If anyone who’s thinking of making the same jump finds this, my takeaways are:
- Transcoding 4K SDR to HD goes from “not possible” to completely practical.
- The newer QSV implementation does not make a quality difference.
- If you optimize a lot of content, I’d suggest turning off hardware encoding, you’ll get more speed and/or quality depending on your encoding preset.
- I’m pretty sure the HW vs SW encoding comparison doesn’t makes sense for streaming. Read directly, it implies the DS918 can handle 3 streams with HW, and 10-11 with software, which just isn’t plausible.
I still haven’t found a clear answer on HEVC and/or 4K encoding, but theoretically the DS918 should support it. If anyone does have solid information on what the plex roadmap is regarding that, I’d love to hear it.
