HifiZine
The enthusiast's audio webzine

Roon Server on ODroid H2

I expect that Roon needs no introduction. In a few short years, Roon has become the go-to music player for many audiophiles. Its extensive set of features includes a consistent, modern user interface across multiple devices, built in DSP (upsampling, EQ, cross-feed, convolution), a transparent networked architecture, and tight integration with popular music services like TIDAL and Qobuz.

There is now quite a long list of “Roon Ready” players listed on the Roon partner devices page. For some time, it’s also been possible to turn a small ARM-based Linux SBC (single board computer) into a Roon player by installing the Roon Bridge software. For the Raspberry Pi in particular, RoPieee is a ready-to-go Roon player distribution that supports most popular analog and digital output cards.

However, the Roon Server requires a more substantial piece of hardware. This sucker ain’t gonna run on your Granma’s Raspberry Pi! All the indexing, cataloguing and connection-making between your music files takes place on the Roon Server, as well as the above-mentioned DSP if you’re using it. Roon refers to the result of this CPU work as “metadata.” In CPU terms, baking and digesting metadata isn’t cheap, so Roon Server requires an x86_64 processor.

Ever since I discovered how easy it is to set up a DLNA music server on a Raspberry Pi or an ODroid HC1, however, I’ve been reluctant to dedicate a “proper” computer as a music server. Even an Intel NUC seemed expensive compared to the Pi and the HC1. Enter the ODroid H2 from South Korean Hardkernel Co., Ltd., a $111 SBC sporting an Intel Gemini Lake Celeron SoC (“system on a chip”) with tolerable benchmark scores, an NVMe socket for a fast SSD, and two SATA connectors for hard drives. I couldn’t help but wonder if that would be enough for Roon Server.

Well, thunk I, there’s one way to find out.

Context and comparisons

Let’s place the H2 into context. First, CPU power. For their dedicated ROCK server distribution, Roon currently recommend the 8th generation NUC8i3BEH for “small to medium libraries” and the NUC8i7BEH for “large libraries.” When I started writing this article in June 2019, their recommendation (here) was the 7th generation NUC7i3BNH and NUC7i7BNH respectively. The graphic below shows the Geekbench scores for these NUCs along with two generations of Mac mini. Since Roon Server makes good use of a multicore processor, I’ve sorted them in order of the multicore score:

ODroid H2 CPU speed compared to others using Geekbench scores

The H2 is slowest…but only just. It’s not far behind Roon’s “small to medium” recommendation as of June 2019, or the 2012 i5 Mac mini that I used as a Roon server for some time without even thinking about performance.

What about pricing? When you order an H2, you will also need the parts to bring it up to being equivalent to say a NUC: case, SATA cables, and power supply. Delivered in the USA that will run you about $170, whereas a NUC8i3BEH from newegg.com is $315, or 85% more. However, you still need to add memory and storage, which will be the same in both cases.

Speaking of storage, Roon strongly recommends that the system drive be an SSD for performance reasons. Both the H2 and Intel NUC have an NVMe slot for a fast SSD*1. For my H2 Roon Server, I’m using the cheapest good quality drive I could find, a Samsung PM961 128GB OEM drive. Below are some measured read and write speeds, in MBytes/second*2.

Drive / computer 4k random read 4k random write Sequential read Sequential write
Samsung 850 Pro 250GB (65%)
2012 i5 Mac mini
20.8 26.1 485 144
Samsung 840 Evo 1TB (75%)
ODroid HC1
21.6 27.4 373 347
Apple APO256 250GB (90%)
2018 i5 Mac mini
53 100 2231 1283
Samsung PM961 128GB (6%)
ODroid H2
60 142 1,500 809
Samsung 970 Evo Plus 250GB (5%)
ODroid H2
61 143 1,500 992
Samsung 970 Evo Plus 250GB (5%)
Intel NUC8i5BEH
57 268 2,300 1,600

Clearly, the NVMe drives outperform the SATA drives by a considerable amount*3. The 970 EVo plus is also an excellent drive, but was quite a bit more expensive and in the H2 has little advantage over the PM961. The 970 Evo Plus performs better in the Intel NUC because the NUC has PCIe 3.0 lanes whereas the H2 has PCIe 2.0.

ODroid H2 with two memory sticks and an NVMe SSD mounted

ODroid H2 with two memory sticks and an NVMe SSD mounted (stock photo from odroid.co.uk)

For music storage, I’m assuming a hard drive or drives will be needed*4. If so, H2 has the advantage, as it can use one or two 2.5″ or 3.5″ drives in addition to the NVMe SSD. The NUC can have only a single internal 2.5″ drive in addition to the NVMe drive; furthermore, with a maximum allowed height of 9.5mm, currently available drives limit capacity to 2 TB. For my H2, I used a 4 TB Western Digital “Red” 3.5″ drive.

As far as storage goes, the Mac mini is a solid last. The 2012 model can be made to carry two 2.5″ drives although with one SSD and one HDD installed, macOS will want to turn them into a Fusion drive. The 2018 model can’t have internal storage changed or added at all.

(*) Notes on this section:

  1. Note that this applies to NUCs with Core processors only – Celeron NUCs do not have the NVMe slot. This makes the Celeron NUCs unattractive for this application because you can’t have an SSD and a hard drive in the same box.
  2. On Linux, these scores were obtained with dd for the sequential read/write times and iozone for the 4k read/write times. On the Mac, scores were obtained with BlackMagic Disk Speed Test for the sequential read/write times and AmorphousDiskMark for the 4k read/write times.
  3. The SATA drives are about 2/3 full and have been in use for some time. Fresh empty drives always benchmark better. Still, the differences here are not small and the SATA interface itself is limited to 600 MB/sec. I’ve indicated the used capacity next to each drive in parentheses.
  4. If you already have your music library on network storage, then the internal storage capability of the server will not be a consideration for you. Here I’m assuming that a self-contained server unit including music storage is desired.

Physical assembly

The H2 is a bare board. You will need to add one or two DDR4 memory sticks. I used a single Samsung 4GB stick. The NVMe SSD slips into the socket also located on the bottom of the board and is secured with a screw thoughtfully supplied by HardKernel.

Odroid offers several different case styles, depending on whether you want no SATA drives (Type 2), 2 x 2.5″ drives (Type 3), 2 x 3.5″ drives (Type 1), or 1 x 3.5″ drive (Type 4). I used Type 4, shown below.

Case “Type 4”. Not elegant, but it serves to hold everything together and it’s fairly cheap.

The case is assembled around the drive, with the side pieces screwed into the drive. With the Type 4, there are ten bits of oddly shaped plastic to be assembled and it’s easy to get something backwards, so I do recommend watching the instruction video carefully. I guess you could say this case is functional, but not convenient – it needs to be dismantled again to swap a drive or a memory stick.

This case doesn’t include a fan, although one could be installed if desired. I didn’t find the fanless H2 to run hot in my testing with Roon: in an ambient of 20 degrees C, I saw CPU core temperatures in the low to mid 40’s while playing music. The highest temperature I noticed was about 64 degrees during initial library load.

In retrospect, the Type 1 case would be a better choice. While it is larger, it’s less fiddly, holds two drives and comes with a fan, so you could hide it in a cupboard and forget about it.

Installing an OS

Since the H2 has an x86 processor, you don’t need a special download for the operating system as you do for ARM processors. Any x86_64 Linux installer should work. For this application, I think stability is one of the more important attributes in choosing a distribution, so I installed Ubuntu Server 18.04 LTS. This is supported until 2023.

Installation is simple. In short, after downloading, burn the image to a USB stick with Etcher. For installation, connect a screen and keyboard to the H2. Insert the USB stick into one of the USB ports and plug in the power. During the installation process, you will format the NVMe SSD and choose a login username and a hostname – I used “roonuser” and “roonsrvr” respectively. At the point where you are asked whether to install OpenSSH server, check the box to affirm. When installation is done, press Return to reboot. The installer will ask you to remove the USB drive and press Return.

Why not ROCK?

ROCK (Roon Optimized Core Kit) is a Linux distribution that runs Roon Server and only Roon Server. It’s only supported for Intel NUCs. While I read reports of ROCK running on other hardware, it won’t run on the H2: ROCK requires legacy BIOS boot but the H2 only supports the newer UEFI boot method.

This is not a concern to me – I prefer to install Roon Server on an existing Linux installation anyway. That way, I can get better visibility into what the machine is doing (see Appendix) or install other services. Still, if Roon were to create a distribution of ROCK that worked with UEFI boot, it would certainly be worth a test install on the H2.

After the reboot completes, log in using the attached keyboard and screen and update the OS:

$ sudo apt-get update && sudo apt-get upgrade -y

You will need this networking utility:

$ sudo apt install -y avahi-daemon

Because the H2 has two network cards and you will have only one of them connected, there is a two minute holdup during boot. To fix this:

$ sudo nano /etc/netplan/50-cloud-init.yaml

Add “optional: true” lines to this file, so it looks like this:

network:
    ethernets:
        enp2s0:
            dhcp4: true
            optional: true
        enp3s0:
            dhcp4: true
            optional: true
    version: 2

Then:

$ sudo netplan --debug generate
$ sudo netplan apply

Finally:

$ sudo reboot

You can now disconnect the keyboard and screen from the H2 and use ssh to log in from another computer. Doing so also makes it easy to copy and paste many of the commands in the instructions that follow.

  • On Mac, use the Terminal.
  • On Windows, you can use Putty, although I would suggest installing WLS (Windows Linux Subsystem) and using that.
  • On Linux, you’re set, just use your shell/terminal.
myname@mycomputer:~$ ssh roonuser@roonsrvr

Formatting and mounting the music drive

The SSD was formatted during the Ubuntu installation process, but you still need to format and mount your music drive. I’ve described this before, so please refer to Sections 2 and 3 of Droidisk – An inexpensive compact music server. Adjust the username and hostname in the instructions to those you chose during Ubuntu installation.

Installing Roon Server

Roon Server is easily installed using the instructions on the Roon website. First, install ffmpeg and cifs-utils:

$ sudo apt install -y ffmpeg cifs-utils

Then run Roon’s “easy install” instructions:

$ curl -O http://download.roonlabs.com/builds/roonserver-installer-linuxx64.sh
$ chmod +x roonserver-installer-linuxx64.sh
$ sudo ./roonserver-installer-linuxx64.sh

And that’s it! Start the Roon UI on a computer or a tablet and you will be able to “connect” to the server running on the H2. Note: if you already have Roon Server running somewhere, like say on a PC or Mac, you will need to “deauthorize” it in the Roon UI before you will be able to connect to the H2.

Once you’re connected, you will be able to point Roon to your music drive in the initial setup wizard.

Getting music onto the music drive

Roon has an awesome trick that I wasn’t aware of until I started writing this section – you can drag and drop files into the Roon UI on your computer, and Roon will upload them to the Roon server. Very impressive.

So that’s one way of getting music files onto the server. Here are a few more:

Does it work?

Yes! It works great. With a library of about 50,000 tracks, I find it to be quite responsive. However, “quite responsive” is a little vague, so I searched for ways I could quantify the UI performance and found this list on the Roon forum.

I worked through the list, timing each by hand. The numbers are quite low, so this is not very accurate but good enough I think to justify my “quite responsive” statement. I was logged into Qobuz while doing this. The timings do vary – repeating the same operation is typically faster. I then repeated the tests with Roon Server running on a 2018 i5 Mac Mini and with the library on an external 2.5″ drive. In both cases, the Roon UI is running on a Wifi-connected laptop. Here are the results:

Item ODroid H2 with internal 4TB drive 2018 i5 Mac Mini with external portable drive
Open Overview page. Two seconds the first time, and between one and two seconds from then on. About two seconds the first time, then a second.
Open Discover page. About a second and a half the first time, and a second after that. About a second and a half the first time, then a second after that.
Perform a search for “The Beatles”. About a second to a second and a half. About a second.
Open “The Beatles” artist page. About a second and a half. Instant.
Open the “Help!” album page. Half a second. Instant.
Start playback of “Help!” (how long does it take before it plays?). A second and a half. A second.
Search for “Daft Punk”. Between a second to 2 and a half seconds. A second.
Open the “Daft Punk” artist page. Half a second. Instant.
Open the “Random Access Memories” album page. Half a second. Half a second.
Start playback of “Random Access Memories”. A second. A second.

According to the CPU benchmark scores shown earlier in this article, the 2018 Mac mini is nearly 4 times faster than the H2, yet the times of various user interface actions are not very different. This suggests that these times are dominated by load time to the laptop (2015 MacBook Air) and rendering time for the user interface.

Summary

Based on the user interface timings above, it seems there’s little to gain from having a faster computer than the H2. Of course, things may be different with a larger library, but I suspect it would have to be quite a bit larger to make a noticeable difference.

The ODroid H2 has so far proven itself to be a very competent little computer. My main reservation is actually the case. Still, it’s workable and once you’ve set it up, you shouldn’t need to mess with it again.

All in all, I’d say it’s a win! Thanks for reading, if you try setting up your own Roon Server with an ODroid H2 or have any questions, please post in the comments below.

 

Appendix A: monitoring CPU load

To monitor the CPU load:

$ htop

This will fill the terminal window with process and CPU usage information. At the top left, the usage for each CPU core is shown, along with the memory usage:

Using htop to monitor CPU usage on the ODroid H2

Type “q” to exit.

Appendix B: monitoring temperatures

To monitor the temperature of the CPU:

$ sudo apt install -y lm-sensors
$ sudo sensors-detect

When you run sensors-detect, accept the default for all questions i.e. hit Return, except at the very end when it asks you “Do you want to add these lines automatically to /etc/modules?”, when you should type YES in response.

Then:

$ sensors

If you want to update the readout continuously:

$ watch sensors

Using sensors to monitor ODroid H2 temperature

Type Ctrl-c to exit.

Appendix C: Starting and stopping

To stop Roon Server:

$ sudo systemctl stop roonserver

To start it again:

$ sudo systemctl start roonserver

To reboot the H2:

$ sudo reboot

To shut down the H2 completely:

$ sudo poweroff

The last is always recommended before unplugging the power. To start it up again after poweroff, press the power button in the corner of the board, shown as “O” in this picture:



            


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