Asustor NAS and the minimum requirements for transcoding what content



Been a lot of questions on this forum and on Asustor's own forums about Transcoding media.  I have TRIED to answer everyone's questions the best I can.  Hopefully this thread will answer some more questions before they get asked.


The unit of measure most software or hardware companies use to compare CPU's is something called a passmark.  This is a series of tests performed on the CPU to give it a rating of the over-all efficiency of one CPU model or series against another.


According to Plex, the minimum specs to transcode a 1080p stream is in the 2000 passmark range.  For 720p streams it's in the 1500 passmark range.  Refer to here for the document:


This gives some VERY basic guidelines, but isn't carved in stone.


So, let's look at various Asustor NAS CPU's and compare them:  (Asustor isn't forthcoming on any of the CPU's installed on any of these devices, so we have to rely on reviewers or taking them apart ourselves to get more info...)


AS-20x series:  This NAS has

  • CPU: Intel® ATOM™ 1.2GHz Dual-Core Processor

  • Memory: 512MB DDR3

Memory in this case isn't as important as the CPU itself, so let's get an idea of what the passmark for this CPU is:


This is the CLOSEST CPU I could find in the list at CPUBenchMark to use to compare to.  This CPU has an underwhelming 218???  As you can see from the link it's not that great...


AS-30x series might be a bit better, let's look:

  • CPU: Intel® ATOM™ 1.6GHz Dual-Core Processor

  • Memory: 1GB Memory DDR3

A little faster, so maybe we're getting into some decent numbers?


Scroll down a ways to find these CPU's... Again we're not 100% sure which one it is, so let's say for argument we take the BEST numbers...  635, so OK, it's almost 3 times better, but guess what...  It's a far cry from where we need to be!


Next we're going to look at the venerable 60x series.  (It's older than all but the littlest boys, so makes sense.)

  • CPU: Intel® Atom™ 2.13 GHz Dual-Core Processor

  • Memory: 1GB SO-DIMM DDR3 (Expandable. Max. 3GB)

WOW, so still can't find the CPU info on this bad boy, so I guess we're back to a guessing game again.


843?  Well, we're STILL a long ways from getting decent 1080p transcoding so what gives here?!?1


We still have a few more to look at, so don't give up hope yet....


The new 500x series would fall in next, huh?

  • CPU: Intel Celeron 2.41GHz Dual-Core (burst up to 2.58GHz) Processor

  • Memory: 1GB SO-DIMM DDR3L (Expandable. Max 8GB)

Now this one we can find out a bit more about...  From this review we find that the 500x series has a J1800 Celeron processor!  (YEAH, ACTUAL specs!)  Shall we find out how this one does?


So we look it up and get:


Humm....  1046.... 


OK, the the same review from Smallnetbuilder said the 510x series is a J1900, so....

  • CPU: Intel Celeron 2.0GHz Quad-Core (burst up to 2.41GHz) Processor

  • Memory: 2GB SO-DIMM DDR3L (Expandable. Max 8GB)¹

This leads us to the actual passmark of:


1900 and some change...  (Ok, not a lot of change, but it's getting up there...)  Still not a full 1080p movie transcode, unless it's a low bitrate and you aren't doing something like subtitles... 


Now, what about the BIG boy...  The new 700x series NAS..

  • CPU: Intel® Core i3 3.5GHz Dual-Core Processor

  • Memory: 2GB SO-DIMM DDR3 (Expandable. Max 16GB)

This thing is a speed demon, by the looks of it.  (Compared to the others at least.)  Reviews tell us this is an i3-4330 and it's in an 1150 socket.  Things are looking good, right?  and ACTUAL CPU in a socket.  Not soldered onto the MB....


This almost is starting to look promising....  Let's get a Passmark on it, shall we?




Passmark here of 5075!  There's 1080p transcoding and then some.  Forget about not doing subtitles, now!  At least for a couple of users...  You got some room to breath with this one...


Let's look at all this in a line now...


AS-20x series   218 passmarks

AS-30x series   350/635 passmarks (Not sure which CPU this has in it)

AS-60x series   843 passmarks

AS500x series  1046 passmarks

AS510x series  1916 passmarks

AS7000x series 5075 passmarks


So, if someone asks why their video is stuttering on their Asutor NAS, you can point them right here and give hard and firm numbers.


Great Post 

i might even try and justify my self to get the 7's right now iam only thinking of the 5's :D

will 7's do 4k?  


just took a look at the 7's, can't justify the price  :( the 5004 are $550 here but 7004 are .......... $1300 :(


The 700x series can do 4K but only through the HDMI or possibly also with LooksGood app.  (Another streaming app, but has sever limitations compared to Plex.)

It does have HW support for the Intel Quick Sync Video since it is a Haswell CPU.  Plex hasn't brought this out to the masses yet, so when they do I'm sure the over-all Passmark requirements for Haswell CPU's will drop significantly.  That means the 5075 passmarks the i3-4330 might be much greater when transcoding video.

This NAS uses a socketed chip as opposed to the others from Asustor which are all soldered in.  As a result of the socket it MIGHT be possible to drop in a faster CPU.  (for example, an i7-4771 I think is also a 3.5GHz but gives almost 10K passmarks.)  I'm not going to risk blowing this NAS up, though unless someone else does it and reports back.  I expect it to take at least a few more months. 

There are some very good reasons to spend the extra coin, if you really need performance.  This NAS is only about $1100 US now... (7004T)  And the 7010T is running under $1900.  That's 10 drive bays!   I expect prices to drop in the next couple of months.


Hi Just wondering if i take time out to convert and download everything is MP4 then transcoding will not be an issue for 1080p?

just found the same CPU on this list

on the QNAP TS-451

it says for my CPU *May transcode some low bitrate 1080p media    what do they mean by low bitrate? 


Bit rate is a combination of things like color depth, screen resolutions, frames per second, audio sampling rates, etc.  The higher any of these are in relation to say a known control, the higher the bit rate of the results.

So a file with 24 FPS is going to be smaller than the same video in 30 FPS which again would be smaller than 60 FPS...  (That's Frames Per Second)

These numbers are all a factor ing determining the bit rate of a given video.  You can get this info for a file in Plex by hitting the movie, and the three dots on the lft side and select info.  (There are a couple of other places you can get this.)

It will tell you how much bandwidth it will take to transmit the stream in the left hand column.

Now, things start getting strange when you throw in subtitles, multiple audio, etc...  Server side resources start being impacted as you start converting things while it's streamed...


And doing the conversions is exactly what I've been doing for a year...  Tired of it, so time to upgrade machines.


icic totally helps most my files are only around 1.6 - 1.8gb 1080p mp4s, so that should be fine? or mp4 wont need transcoding?  


You won't know what the actual bit rate is unless you see the actual data on it...

You need to look at the media specs and see what the bit rate is...  I'm NOT going to tell you it'll work and when it bails out I'm left holding the bag...  :)

Now, if the client supports streaming of the media type, and everything looks/works good, it'll Direct Play...  No transcoding, so no CPU buffering...  Make sure you hit the Web Optimized setting in Handbrake when you redo or make the files...  Everything could be right but that one thing and you're transcoding...

I hope I explained all of this well enough.  There are tons of sources for this kind of information on media and bit rates on the internet.  If you still have questions, Google is your friend...  :)


so just to clarify, when you say no transcoding needed, meaning the e.g. if iphone reads mp4 then if the original sorce is mp4 then we are fine, no coding needed 


You know, this answer is now the 4th one I've typed out for your question....

IF everything is set up right, and

IF the bandwidth is present to support the stream, and

IF you aren't using unsupported subtitles, and

IF the client app from Plex likes the format, codecs and bitrates, and

IF the device itself can handle the resolution, then

You shouldn't have to worry about the server needing to transcode the stream.

You are going to have to start doing some of the leg work here to figure out what's happening on your devices, both server and client.  I've tried to explain why the various models of Asustor's NAS always seem to choke when transcoding.  That was what this thread was about.  the physical why's of the NAS's not being able to keep up...  Not SPECIFICS about a given client and media combination...  You are just going to have to cross that road yourself, armed I hope, with the information I've shown you in this and other threads here.

This is the best answer I can give you.


I wonder what Loadingerror bought!


I assume that the Passmark testing was done in one test environment. How much would it matter if the capacity and speed of RAM were different for each CPU?

For example, compare the Silvermont class of Celerons in the Asustor AS6204T to the QNAP TS-451+ with these configurations:

  1. QNAP - Intel J1900 (Bay Trail-D - Oct 2013) @ 2 Ghz with 2Gb DDR3L RAM @ 1333 Mhz
  2. QNAP - Intel J1900 (Bay Trail-D - Oct 2013) @ 2 Ghz with 8Gb DDR3L RAM @ 1333 Mhz


  1. Asustor - Intel J3160 (Braswell - Jan 2016) @ 1.6 Ghz with 4 Gb DDR3L RAM @ 1600 Mhz
  2. Asustor - Intel J3160 (Braswell - Jan 2016) @ 1.6 Ghz with 8 Gb DDR3L RAM @ 1600 Mhz

What would the Passmark rankings (from best to worse) be with these different RAM capacities and speed environments?


I took the passmark info directly from the website, where they take real world tests and average them out. I would guess that most times, they are running these tests on Windows platforms, and that the ram may have some differences in results. But these are AVERAGED values. (In some cases from hundreds or thousands of tests.)

I linked to each of the results for each CPU I mentioned in the OP. For example, the i3-4330 CPU in the 7004T was originally listed as a 5085 passmark CPU. It’s now showing 5062 as the average, but 3 months ago was showing 5045. When I made this post it was showing 5075. These values are averaged across all of the tests for that given CPU. There have been 396 CPU’s tested to make up the current passmark score for this CPU model, if you look at the link. The margin for error is considered “Low” based on the number of tests run, and the ranges of the results those test gave. Some hardware configs might produce higher results, while other hardware might have lower results. This is why the results are averaged.

While your individual results may vary a bit from those published at the site, I wouldn’t expect anything to be night/day different. The results of the tests done by cpubenchmark is an expectation of the CPU power each make/model of CPU is capable of producing. You also have to remember, I put this together when the 5x0x series were just coming out, so it’s missing the 3x0x, 6x0x and 100x series of CPUs. As none of them are any faster than the i3-4330, I haven’t updated this post to reflect them. (And likely won’t until a faster, more capable CPU hits the Asustor line.)

The biggest reason I put this whole thing together is because people were coming onto the forums complaining their NAS was buffering. Well, yeah it’s going to buffer when you are transcoding a 1080p 12Mbps stream on a NAS with only 1000 or so passmarks. It doesn’t have even close to the minimum specs needed to do the job. (For a 1080p 12Mbps, it’s going to take roughly 3K passmarks to do in RT.) As I own Asustor products, I didn’t even look at the QNAP or Synology product lines. Looking at the CPU’s in them and the results I have here, should give rough approximations of what their products are going to have, though… Do your own research to find your CPU model and what it’s passmark is.

For example, the QNAP models you listed have a J1900 CPU in them. (Similar to the CPU in the 520x Asustor model) So they are going to be roughly 1900 passmarks. Where the J3160 CPU in the Asustor 620x series is showing 1831 passmarks with 21 samples tested. They say this has a low margin of error, even though the sample counts aren’t that great. So this tells me they had several tests with very similar numbers. If there were extreme swings in the results, their margin of error be high instead.

So neither of these CPU’s you asked about are going to be able to perform a full 1080p 8Mbps transcode session in RT without some buffering. (Transcode speeds are likely to be around 0.6-0.9 if you log file dive for the info.) 1080p 12Mbps is going to be even slower on transcoding, so expect those speed scores to be even lower.

The memory isn’t a factor very much in these tests, as transcoding is really just number crunching, and memory isn’t going to play a huge factor when it comes down to the actual crunches that need to be made. While it may give you small gains, it’s not going to raise a low end CPU into a different class or significantly raise the over-all score the CPU is capable of hitting.

All of this just highlights you need to take the time to prepare your media if you are going to use a NAS with either of these models of CPU. (Make sure you have the media in the most Direct Playable file, codecs and bitrates your client apps support.) Having the right hardware to support your target client app is as important as the media preparations you do. This means you need to test the media with your client, make changes and test again. Don’t assume you have everything right until you have tested 20-30 different files without a failure.

If you have a low end CPU, and your client asks for media in a way that requires that CPU to transcode, you aren’t going to be happy with the results. If you have the media prepared for the client’s request, everything should work pretty well. If you have a CPU that can handle transcoding it’s not going to matter much, until the CPU has too much going on, then something will buffer…

Remember, the CLIENT makes the requests of the server. And the server delivers media based on the client’s request. If your media is right for the request, you can run a NAS with 200 passmarks. I know, because I have done it. If the media is wrong, it’s going to take horsepower to convert it. I’ve done this as well, with the 7004T I have now.



I hope you did not get the impression that I was disputing your original post. I just wanted to know if differences in RAM capacity and speed would make much difference IN TRANSCODING. As the saying goes for computing power, just add more RAM…I guess NAS units are different. BTW, I was surprised that the QNAP had a better rating with its 3-year old CPU than Asustor’s more expensive 1-year old CPU.

It is a darn shame that the VAST majority of a Manufacturers NAS units are pitiful at transcoding. A better range is needed. The jump from the 60xx series to the 70xx series is way too much of a jump (including price) and is the ONLY model that can fluently transcode,

Keep up the good work!


No, I didn’t feel you were disputing my post, but I don’t think you looked at the links in it before you asked the question. Had you done so, I think you would have realized that your question already took into account differences in hardware as a part of the test. Or seen the J1900 was already covered in the first post. As I said in the reply to you, differences in RAM are already taken into account when you look at the scores. The scores of the various CPU’s get are averaged, best case, and worst case, to give a score that represents the typical install.

There aren’t a lot of CPU choices for something in between those models. The J1900’s are nearing EoL and that means getting the chips is only going to get harder. So the J3160’s in the 620x series is the “replacement”. There are other things in the NAS itself that make up for the CPU or lack of it, that make the model still viable, for everything except transcoding media.

I was hoping that Asustor’s model 100x was a jump in CPU instead of a lower powered unit when they were first announced. (As in I had hoped they were an i7 model and not the underpowered ones they really are.) I’ve talked with the folks at Asustor about upgrading the 70xx series with i5’s and i7’s, and they have identified chips that will work in the 8’s and 10’s, but nothing that works in the 4’s. The case is too small for heat sink needed for adequate cooling for the bigger CPU’s.

You get what you pay for. I bought a HT appliance that I expect to work in that capacity for at least another 3 years, and likely 5. The only thing I’ll need to do with it is add more drive space to it as my needs increase. The CPU can easily do what I task it to do. The same can’t be said of the lower end models.


I opened all the links within the article…but what I did do was to mistake your signature for all the other links. I just figured it was describing your system specs as others do. My bad…but I do get some slack here because I am old and it is in small print. :wink:


Age is relative man… Today I woke up and felt 15. Yesterday I woke up and felt 105. the whole day is colored by how you wake up, I find. relative to that first 5 or 15 minutes of the morning… :slight_smile: I actually fall somewhere in the middle of that range, but seldom wake up feeling my own age. And as I get older I seem to wake up feeling on the older age of the spectrum more and more… :confused:

If I make the links and such any larger, I get a warning from the forum mods for spamming… :slight_smile: