Tuesday, May 20, 2014

Part 1: First look at the fanless Atom NUC (DE3815TYKHE)

The Fanless NUC

The new DE3815TYKHE NUC is the first NUC to come without a fan. It's also the first NUC that is based on an Atom CPU. I'll have a look at the box and it's performance. It's available as a mainboard-only version (DE3815TYB) or a full standalone kit (DE3815TYKHE). As the kit is only 20-30 dollars or euros more expensive, it's rather good deal considering you get the case and the power supply for that price.

I'll have a look at the full kit here. In part 1 I will review the new hardware and in part 2 I'm going to look at the question: does it pack enough punch to be used as a HTPC or is it hopelessly underpowered? After all, a Raspberry Pi is able to run OpenELEC...

The case is a bit larger than the previous NUCs had.


The processor is a 1.46 GHz Atom E3815 processor that is a member of the Bay Trail family. It is only a single core CPU but the TDP is only 5 watts. This means that this CPU does not need active cooling so it is possible to build a PC without any moving parts. The GPU is an HD Graphics GPU with 4 execution units that is clocked at 400 MHz and there is no boost available. The board will take a single DDR3 SODIMM with 1.35V voltage. Maximum amount of RAM is thus 8 Gb.

Old school VGA connector in the back.

The device is very much intended for embedded systems. There is even serial port header on the main board but the NUC kit does not have a physical serial port. However, the NUC has a physical VGA connector, which I have not seen on consumer PCs for some time already. For embedded systems that might come handy though. In addition to the VGA connector, there is a full size HDMI connector at the back of the NUC.

When it comes to attaching peripherals to the NUC you've got one USB 3.0 port on the front of the chassis and two USB 2.0 ports at the rear. There's also an internal header for two more USB 2.0 ports. In addition to the USB ports you've got a combined microphone/headphone jack. Internally there is one Mini PCIe half size slot that could be used to attach a WiFi adapter for example. The WiFi antennas are built into the case. Wired Gigabit Ethernet connectivity is provided by the integrated Realtek adapter.

Interestingly the device contains 4 GB internal eMMC flash memory. This is enough to install the OpenELEC media center OS on it, so in theory there would be no need to add a drive to the device - just plug in your memory module and you're ready to go. The chassis holds space for additional 2.5 inch SATA drive.

Features of the NUC


No components installed in this NUC yet.

The case can be opened by unfastening a couple of screws on the bottom of the case. Adding a memory module is straight forward.

Note the SATA connectors on the left side of the case.

In case you want to add an SSD or HDD drive, the SATA connector is prewired and there is no need to add a SATA cable.

Single 1.35V DDR3L SODIMM and a WiFi adapter installed.

Installing the memory module in to the case was easy after having done it with the i3 NUC. Just remember to buy 1.35V DDR3 SODIMMs (Amazon), 1.5-volt modules won't work! The antennas for the WiFi adapter are built in to the chassis, so adding a half size Mini PCIe WiFi adapter was straightforward.

The BIOS is the standard visual BIOS that Intel has shown us already with the other NUCs. For some reason the NUC did not boot initially. It gave me no chance to enter the BIOS and tried to PXE boot directly. I had to pull the yellow BIOS security jumper out, restart the NUC and reinstall the jumper in its place before the system booted up correctly. Don't know the reason for that really. After that the NUC has been ok and has booted up ok from USB2 flash sticks and USB3 external hard disk that I have.

Installing Linux


I booted a Lubuntu 14.04 installer from a USB stick and successfully installed Lubuntu on the internal eMMC storage that is built-in to the NUC. Booting up the system is not lightning fast, but not slow either. The window manager works nicely and surfing the net with Firefox was fine. Overall I was surprised how snappy the system was keeping in mind that it's powered by a meager single core Atom CPU. Opening several applications simultaneously turned the system into a sluggish mode.

This is what /proc/cpu tells about the CPU:

processor : 0
vendor_id : GenuineIntel
cpu family : 6
model  : 55
model name : Intel(R) Atom(TM) CPU  E3815  @ 1.46GHz
stepping : 3
microcode : 0x31e
cpu MHz  : 532.000
cache size : 512 KB
See the full output here.

The internal eMMC disk will show up as /dev/mmcblk0. The partitions on the eMMC will be /dev/mmcblk0p1, /dev/mmcblk0p2, /dev/mmcblk0p3 etc. The  /dev/mmcblk0 can be handled with all standard tools such as fdisk. In case you don't see the device you probably don't have the correct kernel modules either built-in to the kernel or loaded. In Ubuntu 14.04 this was taken care of though, no action was necessary.

If you decide to compile your own kernel, the following options should be enabled to support the eMMC disk:


If you don't need to boot from the eMMC, you can configure these as modules and load them at boot.

eMMC Performance


In order to test the eMMC performance, I first wrote a 1-gigabyte file:

$ dd if=/dev/zero of=tempfile bs=1M count=1024 conv=fdatasync,notrunc
1024+0 records in
1024+0 records out
1073741824 bytes (1,1 GB) copied, 87,8031 s, 12,2 MB/s
As you can see, this took a while. I then rebooted the system to make sure no cached data exists and run the following:

dd if=tempfile of=/dev/null bs=1M count=1024
1024+0 records in
1024+0 records out
1073741824 bytes (1,1 GB) copied, 25,8199 s, 41,6 MB/s
Now I don't claim this to be a very comprehensive test for the read and write speed, but a read speed of around 40 megabytes per second and write speed of 12 megabytes per second isn't actually superfast these days. You can probably find USB memory sticks that are faster than that. Anyhow the performance is acceptable and as with all the other components in this NUC, it was not designed to be a performance king from the beginning.


Overall, it's this NUC is so clearly aimed for embedded device markets that it's a bit difficult to see much desktop use for this. The single core Atom CPU just is not going to cut it if you plan to do anything heavier. Some people might be interested in using it as a silent, fanless HTPC and in the part 2 of the article I'll evaluate how well it suits that purpose. However, I believe there are other products - even within the Intel NUC product line - that are a better match for that use as well. Since there are no mechanical moving parts in this NUC it would make a perfect worry free system for digital signage or a info kiosk running in a mall or airport for example.

Maybe this could be used to create a very low power home server, when the processing power needs are modest. Or it could serve some specific development purposes. I did not try Windows on the machine and I don't see this NUC as a good platform for running Windows. Intel claims to support Windows 8, Windows 8 Embedded and Linux.

The price of this NUC is pretty much on par with the DN2820FYKH (Amazon) - the Celeron Bay Trail NUC, so we cannot avoid making the comparison between these two. The DN2820FYKH sports a much more powerful 2.4 GHz dual core CPU and still has extremely low TDP of 7.5 watts.

Reasons to choose DN2820FYKH
  • Dual-core CPU packs more grunt
  • GPU clock of 756 MHz vs. 400 MHz
  • IR receiver is integrated
  • WiFi adapter included and preinstalled 
  • Smaller case

Reasons to choose DE3815TYKHE
  • No fans
  • Internal 4GB eMMC storage
  • VGA connector
  • Interfaces for embedded device use (serial ports, eDP, etc.)



  1. as your test for the flash performance was the only solid benchmark i found on that device at all...can you test if the cpu is capable of generating at least 100mbit tx?

  2. I have not been able to get the installation to work for eMMC install. I have installed on USB stick but that is of no help. Could you share how you were able to do it? BIOS update? BIOS setting change? other methods? Any help would be great. Thank you.

    1. @tundal:
      Did you set the BIOS for Linux OS? (Advanced, Boot-Configure)
      Are you using Lubuntu 14.04? (I couldn't get 12.04 to work for me.)
      Are you installing to a single, primary ext4 'root'-partition on the eMMC?

  3. Tracing your footsteps here, (with Lubuntu 14.04 on a NUC-DE3815TYKHE,) but cannot get the system to shutdown or reboot upon completion. Have you encountered this problem? I've seen other posts about this issue, but not as they apply to this particular machine. Would really like to hear more about your experience on this point.

    1. Update: After one more System-Update, my NUC is shutting down & restarting as expected!

  4. I try to install Ubuntu 14.04 Minimal on the internal 4GB eMMC. Problem is that it doesn't show up for partitioning. I opened a console and navigated to /dev ... no mmcblk0 present. What am I doing wrong?

  5. Are you sure that the Ubuntu 14.04 minimal has the required modules to use the MMC disk?

    If you can run lsmod in the terminal, to check that you have mmc_core and mmc_block at least, that could give you more hints.

  6. Hi, I'm having the exact same problem. I also assumed they were missing so I've tried Ubuntu Server and Lubuntu alternate - neither load the correct modules for the partitioner to the disk.

    Also tried Ubuntu 14.10 server in case it's been fixed in the newer release.

    The good news is that I can install Lubuntu full to the EMMC in UEFI mode, however this bring with it lot of unnecessary packages. . I'm sure there must be a command to bring up the MMC support, just can't figure out what it is...


  7. Hi Folks,
    +1 for me here. Same problem. From what I can tell, the default boot installation ISOs do not come with the MMC support. ie no mmc_block, sdhci and sdhci-pci. Now you can load these manually by going alt-ctrl-f2 during the install, mounting a second USB device with the kernel modules on it and then doing an insmod, however this seems really clunky and not a nice way to do things. Suggestions are appreciated.

  8. I have successfully installed Salixware 14.1 (slackware) with custom Linux kernel version 3.17.2 on the eMMC. Some notes:
    - The default Linux kernel 3.10.7 have no support for the graphics cards
    - Lilo doesn't work, so I am using syslinux as bootloader with custom initrd
    - You should stick to BIOS version 0024. The newer BIOS have bug that Linux will be hang on shutdown/reboot.