GMK NucBox Review – A palm-sized Windows 10 mini PC

GMK released their diminutive mini PC called the NucBox a while ago however they have recently updated the BOM with a new fan and WiFi module together with changing their logo from GMK to GMK TEC. GMK sent the new NucBox for review and the results from various testing are detailed below.

Hardware Overview

The NucBox physically consists of a 62 x 62 x 42mm (2.44 x 2.44 x 1.65 inches) rectangular metal case with a plastic top and base plate. As an actively cooled mini PC, it uses Intel’s 14 nm J4125 Gemini Lake Refresh processor which is a quad-core 4-thread 2.00 GHz processor boosting to 2.70 GHz with Intel’s UHD Graphics 600.

The front has just the power button whilst the rear includes two USB 3.0 ports, an HDMI port, and a Type-C USB port for power. The left side has a microSD card slot and a headphone jack and there is nothing on the right side.

The review model included soldered-on 8GB DDR4 2133MHz memory operating in dual-channel:

and a 128GB M.2 2242 SATA drive which is accessed by removing the bottom base plate:

Additionally, there is a soldered-on Intel Wireless-AC 9461 WiFi 5 (or 802.11ac) module with the internals of the device consisting of two stacked motherboards:

on top of which sits the fan.

The user manual specifications states:

However, the actual WiFi module is only 1×1 and not the stated 2×2 which the Intel Wireless-AC 7265 module would have provided. This, according to GMK, is due to the global shortage of WiFi modules resulting in specification changes between production batches which cannot be reflected in the user manual. Also as there is no Ethernet port a USB-Ethernet adapter (‘dongle’) is required for ‘Support external Ethernet’.

NucBox package contents

In the box, you get a power adapter and cord, a separate plug adapter appropriate for your country, and a user manual.

Review Methodology

When reviewing mini PCs I typically look at their performance under both Windows and Linux (Ubuntu) and compare them against some of the more recently released mini PCs. Since the start of 2021, I’ve been reviewing using Windows 10 version 20H2 and Ubuntu 20.04 LTS however as a result of Windows updating and due to an issue with Ubuntu on the NucBox this time I have reviewed with both Windows 10 version 21H1 and Ubuntu 20.04 LTS & 21.04. I tested with a selection of commonly used Windows benchmarks and/or equivalents for Linux together with Thomas Kaiser’s ‘sbc-bench’ which is a small set of different CPU performance tests focusing on server performance when run on Ubuntu. I also use ‘Phoronix Test Suite’ and benchmark with the same set of tests on both Windows and Ubuntu for comparison purposes. On Ubuntu, I also compile the v5.4 Linux kernel using the default config as a test of performance using a real-world scenario.

Prior to benchmarking, I perform all necessary installations and updates to run the latest versions of both OSes. I also capture some basic details of the device for each OS.

Installation Issues

After installing and booting Ubuntu 20.04.2 the ‘dmesg’ was flooded with ‘snd_hda_intel 0000:00:0e.0: No response from codec, resetting bus:’ errors and the system initially hung:

When it did respond neither HDMI nor the speaker audio worked:

As a result, I rebooted using the kernel parameter of ‘snd_hda_intel.enable=0’ to disable audio completely in order to avoid the freezing issue:

which results in a dummy output:

After some troubleshooting, I tried installing Ubuntu 21.04 and this fixed the HDMI audio issue:

However, audio still did not work from the 3.5 mm headphone jack as nothing was detected or consequently changed when headphones were connected including nothing in ‘dmesg’ when connecting/disconnecting headphones or when listing the ALSA audio devices:

More importantly, with Ubuntu, the NucBox’s fan doesn’t get detected correctly. If the CPU temperature is below 55°C when booting the fan will never come on, otherwise, the fan stays on continuously. The problem of running without the fan is that as part of thermal throttling the values for ‘PL1’ and ‘Tau’ are reduced and they are not reset once the CPU cools down. This results in the throttling being permanent until a reboot. For example, running Passmark on Ubuntu with the fan running gives a score of 3107.82 but if the CPU has been throttled it only gives a score of 467.34. GMK’s solution for Ubuntu is to ‘disable’ the ‘Smart Fan Function’ in the BIOS which makes the fan run permanently:

Finally one of my personal dislikes is having to use plug adapters. As you can see from this photo:

the power adapter has to be inserted into the plug adapter which in turn goes into the plug socket. Although small the power adapter has weight and the plug adapter has a certain amount of ‘play’ that makes the whole tower of adapters slightly wobbly.

Windows Performance in GMK NucBox

Initially, the NucBox comes installed with a licensed copy of Windows 10 Home version 2004 build 19041.685. After upgrading to version 21H1 build 19043.1023 (as version 20H2 is not offered as an upgrade option), a quick look at the hardware information shows:

A brief check showed working audio, micro-SD, Wi-Fi, and Bluetooth. Testing with a USB to Ethernet dongle confirmed that Ethernet also worked.

I then set the power mode to ‘High performance’ and ran my (2021) standard set of benchmarking tools to look at performance under Windows:

For my specific set of Phoronix Test Suite tests the results were:

All these results can then be compared with other recent mini PCs:

showing the results are in line with other mini PCs using the same J4125 CPU.

GMK NucBox Ubuntu Performance

After shrinking the Windows partition in half and creating a new partition I installed Ubuntu as dual boot. Initially, I installed Ubuntu 20.04.2 for the performance testing using GRUB to disable audio and setting the fan to be always on via the BIOS (see Installation Issues above).

After installation and updates, a brief check showed working microSD, Wi-Fi, Bluetooth, and Ethernet when using a USB-Ethernet dongle. However audio did not work as mentioned above.

The key hardware information under Ubuntu 20.04.2 is as follows:

I then set the CPU Scaling Governor to ‘performance’ and ran my Linux benchmarks for which the majority of the results are text-based but the graphical ones included:

I also ran Passmark PerformanceTest Linux:

which can be directly compared to the results from running the CPU test in Windows:

For the same set of Phoronix Test Suite tests the results were:

The complete results together with a comparison against other recent mini PCs are:

and are again in line with other mini PCs using the same J4125 CPU.

4K video playback in browsers & Kodi

I then overwrote this installation using an Ubuntu 21.04 ISO as this provides HDMI audio and tested graphical performance with the fan always on.

For real-world testing, I played some videos in Edge, Chrome and Kodi on Windows and in Firefox, Chrome and Kodi on Ubuntu. The following tables summarise the tests and results for each:

Gaming

As can be seen from the above Unigine Heaven scores the NucBox will only offer limited gaming performance.

Windows vs Ubuntu

Whilst a detailed comparison between the two operating systems is beyond the scope of this review, it is worth noting some of the key findings I observed. Looking at the performance tools common between the two OS showed that they were reasonably evenly matched.

However, as the fan is not detected under Ubuntu and video playback on WIndows runs better than on Ubuntu, given the price includes a Windows 10 Home license it probably doesn’t make too much sense to use the device as a Linux HTPC.

NucBox Thermals

The NucBox uses active cooling and under Windows this works fine:

It has a reasonably quiet fan which when running measured around 41 dBA on my sound level meter next to the device.

However, as already mentioned under Ubuntu the fan is not correctly detected with it either staying off if booted when the CPU is under 55°C otherwise staying on permanently. Without the fan, thermal throttling reduces the values for ‘PL1’ and ‘Tau’ which are not reset once the CPU cools down. This can be demonstrated by monitoring these values during and after a ‘stress’ test. With the fan off and the test running for five minutes:

the thermal throttling of ‘PL1’ and ‘Tau’ happens after just three minutes whereas they remain unchanged during a twenty-minute test with the fan on:

Interestingly the thermal throttling doesn’t affect playing a video under Kodi:

However, it obviously affects CPU performance:

where the throttled Passmark result of 467.34 can be compared to a result with the fan running of 3107.82 (see above).

Networking

Network connectivity throughput was measured on Ubuntu using ‘iperf’:

The poor performance shows the impact of using a 1×1 WiFi module.

Power consumption

Power consumption was measured with the default BIOS fan settings for Windows and when setting the fan both off and on for Ubuntu as follows:

• Initially plugged in – 0.1 Watts
• Powered off (shutdown) – 0.1 Watts (Windows) and 0.1 Watts (Ubuntu)
• BIOS*  – 3.3 Watts (no fan) / 3.7 Watts (fan)
• GRUB boot menu – 3.3 Watts (no fan) / 3.7 Watts (fan)
• Idle – 2.2 Watts (Windows fan not running) and 1.7 Watts (Ubuntu no fan) / 2.1 Watts (Ubuntu fan)
• CPU stressed – 9.3 Watts (Windows ‘cinebench’) and 9.7 Watts (Ubuntu ‘stress’ no fan) / 10.0 Watts (Ubuntu ‘stress’ fan)
• Video playback** – 6.6 Watts (Windows Edge 4K30fps) and 10.0 Watts (Ubuntu Chrome 1440p30fps no fan) / 10.2 Watts (Ubuntu Chrome 1440p30fps fan)

*BIOS (see below)
**The power figures fluctuate so the value is the average of the median high and median low power readings.

As can be seen, using the fan in Ubuntu adds about 0.4 Watts to power consumption when the CPU is idle.

NucBox Drivers

On the GMK website, there is a download link for the Windows drivers together with a modified Windows ISO which includes the drivers but these have not been tested as part of this review.

BIOS

After powering up the NucBox, hitting the F7 key results in a boot menu that includes access to the BIOS. The BIOS is unrestricted:

Final Observations

Overall this is a cute mini PC. However, it is not without limitations. Being so small it only has two USB ports and ideally, a third port is useful to avoid needing a USB hub when using a wired keyboard and wired mouse. The choice of an ‘alternative’ WiFi module is disappointing as the single antenna leads to poor network performance. Finally, the failure to recognize the fan correctly in Ubuntu and HDMI issues when using the latest LTS release probably means this mini PC is best suited to only running Windows.

Highlights	Limitations
Small size	WiFi limited to 1x1
	Ubuntu support issues

I’d like to thank GMK for providing the NucBox for review. It currently retails for under $200 for the tested configuration on Amazon, Banggood, or GMKTec store where you can use the promo code ‘KB1’ to drop the price by $40 and get a gift of a USB hub which includes a Fast (100Mbps) Ethernet port and three USB 2.0 ports.

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