Beelink BT4 Mini PC Review – Slow, Buggy, Fan-cooled, and Overheating

Intel’s low-cost chip shortage has been so bad that Beelink has had to demothball some Atom chips when creating their new mini PC the Beelink BT4. This is one of the cheapest new mini PCs recently launched and uses the somewhat now old Cherry Trail Intel Atom x5-Z8500 CPU which was launched at the start of 2015 and is a quad-core 4-thread 1.44 GHz processor boosting to 2.24 GHz with Intel’s HD Graphics.

The BT4 is the same form factor as the more recent Beelink mini PCs being a half-thick ‘NUC’ style device physically consisting of a 120 x 120 x 22 mm (4.72 x 4.72 x 0.87 inches) plastic rectangular case. This is not a passive device as it contains a small fan that stays on after the device has been shut down. The front panel has only a blue ‘power’ LED and the rear panel includes the power button, power jack, VGA port, HDMI port, a gigabit Ethernet port, and a headphone jack. On the left side there are a couple of 3.0 USBs and on the right side are a couple more 3.0 USB ports and a micro-SD slot. The full specifications include:

The BT4 comes with 64GB eMMC with pre-installed Windows 10 Home (version 1903 OS build 18362.418) together with 4GB of soldered DDR3 RAM.

In the box you get a mounting bracket with screws for attaching the device to behind a monitor together with a couple of HDMI cables, a power adapter, a manual, a service card and a ‘satisfaction’ card:

Starting with a quick look at the hardware information shows it is aligned to the specification:

I first tried to update Windows but it wasn’t a smooth process with the system sometimes freezing, Windows updates crashing or just random reboots. Eventually, I managed to update Windows to version 1909 OS build 18363.535 so I then installed my standard set of benchmarking tools to look at performance under Windows. After running CrystalDiskMark:

I ran 3D Mark’s Ice Storm:

which yielded a very low score. So I ran ‘HWINFO’ to look at the internal temperatures:

which although high didn’t include any indication of thermal throttling. So I carried on and ran 3D Mark’s Cloud Gate:

which resulted in another unusually low score but again with no signs of thermal throttling:

Meanwhile, the external temperature of the device was sitting at around 53°C with a room temperature of just over 28°C. Interestingly the cheap plastic feel to the case actually makes it feel less warm when compared to a metal cased device like the T45 at the same external temperature and whilst you might think the fan would be working its hardest because of the temperature it is surprisingly quiet. Pushing my luck I tried to run 3D Mark’s Sky Diver but the screen froze with the following error:

A quick reboot and running Sky Diver gave the same error. Decidedly unimpressed at this point with the benchmark results so far I then uninstalled the untested ones and installed Chrome instead. Running Octane 2.0 gave consistent results with a representative average of:

and which, unsurprisingly by now, was much lower than expected.

Given the price of the BT4 and because it had two output port types it seems likely that the device would appeal more as an HTPC than as a workstation so I decided to focus more on reviewing its video playback capabilities.

For this ‘real-world’ testing, I played videos in Edge and Kodi in Windows. Normally I start by testing 4K playback quality but neither this option nor 1440p were available in Edge:

yet they were available in Chrome:

There’s a good reason why they should be omitted from Chrome as the results table further below will show and the video playback performance in general under Chrome is not very good.

Keeping an eye on the internal temperatures one thing I did notice was that after playing a couple of videos thermal throttling occurred:

Feeling on a roll now as despite the throttling Windows had been stable without any freezes or reboots so I tried to run the remaining benchmarks I still had installed, namely Passmark:

followed by Novabench:

One point I had noticed earlier was that in the configuration the power limit was set at one second:

and that there was no performance power plan available:

so the device was running at its upper limits in terms of power and temperature tolerances.

Next, I shrunk the Windows partition and created a new 15GB partition so I could install and dual boot Ubuntu using an Ubuntu 18.04.3 ISO:

However, on booting the liveUSB I immediately ran into the system freezing. I remembered that this was a common issue with Ubuntu on Cherry Trail devices so I respun the Ubuntu 18.04.3 ISO using my ‘isorespin.sh’ script with a ‘-g’ option of ‘intel_idle.max_cstate=1’. Fortunately, I could now boot and install Ubuntu and after updates, a brief check showed that everything was working including WiFi, Bluetooth, Ethernet, and HDMI audio although headphone audio had a slight problem in that the right speaker was quieter than the left. Checking the connection and I noticed that the jack doesn’t want to fully insert so this could be the reason. I then ran some basic commands to look at the hardware in more detail:

At this point, the BT4 suffered a random reboot so rather than struggle to run more benchmarks that would really only highlight the now poor performance of this CPU I went straight to the ‘real-world’ testing of playing videos in Firefox, Chrome, and Kodi in Ubuntu.

The results were similar to Windows in that the BT4 is only good at playing 1080p@30fps and H264 encoded videos. The following tables summarise the tests and results for each of web browsing, Kodi in general and Kodi playing specific videos:

An interesting phenomenon was seen whilst playing an HEVC in Windows in that it played in slow motion resulting in the elapsed time exceeding the length in time of the video:

As previously mentioned the BT4 includes a fan and the reason why it is whisper quiet in operation is because it is tiny and useless as we will see later:

It sits on top of a relatively small heatsink:

that covers about half of the entire board:

The device does get hot. During usage the maximum temperature I recorded on the top of the device was 55.9°C:

noting that the ambient room temperature was 31.4°C as it was a hot day with the outside temperature reaching 44°C (111°F):

At the same time, the noise level was quiet and recorded at 36.5 dBA.

However, it is questionable as to whether the cooling solution really works. Under Windows I played a video in Edge followed by the same video in Kodi both for about six minutes:

Thermal throttling was observed and after about five minutes the temperatures dropped to around 65°C/72°C which seems to be the idling temperature under Windows:

Under Ubuntu, I ran an H.264 video in Kodi for 20 minutes and the internal temperature whilst it climbed almost immediately remained consistently in the low eighties reaching a peak of 85°C:

(note the 4 skipped frames occurred when opening and setting up the monitoring programs)

It took nearly the same amount of time (around 20 minutes) to cool down to Ubuntu’s idling temperature of the low sixties:

Once cooled down I ran Octane 2.0 in Ubuntu:

as I was now starting to understand this device. In fact, earlier I had also re-run some Windows benchmarks having allowed the CPU to cool down to its idle temperature and the results showed a marked improvement to the first time I ran them:

However, this only serves to highlight the impact of the poor cooling solution to the overall performance capability.

The astute reader may well ask at this point whether I tried to rerun 3D Mark’s Sky Diver. Well, a couple of days later I did just that after spending about an hour trying to boot Windows as it kept freezing immediately after logging in. I recorded the initial temperature before the test:

and the temperature immediately after 3D Mark crashed with the same error message as before:

So despite it being a cooler day with the room temperature only 25.6°C (yes that is relative compared to the other day when testing) thermal throttling was still occurring.

It is because of these high CPU temperatures and the (likely resultant) instability of Windows that I would carefully consider these issues before purchasing this device.

I’d like to thank Beelink for providing the BT4 for review. It currently retails at around $120 from the various Chinese mini PC resellers.

Ian W MORRISON (Linuxium)

Ian is interested in mini PCs and helps with reviews of mini PCs running Windows, Ubuntu and other Linux operating systems. You can follow him on Facebook or Twitter.

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