Sunday, 21 Oct 2018

AUKEY CB-C55, USB-C hub with Ethernet, HDMI and VGA

Today under review is the AUKEY CB-C55. As we wrote in our first impression, when unboxing this adapter you immediately get the feeling that it’s a solidly built device. The shell is milled from a single piece of aluminum and is the main reason for that nice look and feel; it feels good in the hand and while light, obviously can take a beating.

That design decision is unfortunately also the reason that the port layout is a bit awkward. When all ports are in use, it’s easy to make the cabling messy. It also does not leave a lot of room between ports; some USB sticks are bigger than others and if yours is any size above average then it will not fit.

As for the innards, the chipset used is the good old VIA Labs VL813 chipset. This is almost always what we see in these smaller USB-C hubs. It delivers USB 3.1 gen 1 (5 Gb/sec) speeds.

Data transfers

We connected a Samsung 850 EVO SSD to the hub (in an Orico enclosure) and ran AmorphousDiskMark. Performance was excellent; connecting the SSD directly to the computer is a tiny bit faster but in practice that won’t matter. There was no difference between either port on the hub.

Performance of a 250 GB Samsung 850 EVO connected to the AUKEY CB-C55 hub

You do have to pay attention; there are two USB 3 ports on the hub. One of them is marked 0.9A and one is marked 0.5A thus is not able to deliver the full USB 3 charging power.

When we connected the CalDigit Tuff external harddrive to the 0.5A port, we got subpar results because of the lack of power. Admirably the drive worked, but the write speeds were much lower than what we expected. So do pay attention and don’t hook up power consuming devices to that 0.5A port.

We did other tests, like moving files from one connected drive to another, testing for WiFi interruptions during those operations and checking the temperature of the hub but these all were positive.

Power usage and delivery

As noted before, the two USB-A ports deliver 4.5W (5V @ 0.9A) and 2.5W (5V @ 0.5A). In a pinch, it’s fine but nothing special.

The real power of this hub however is the amount it can provide to the laptop. Although a tiny package, it delivers 51W to our 15″ MacBook Pro. Unless you’re going to peg the CPU at 100% for more than an hour, that’s more than enough to get through the day. We also put the hub between a HP Chromebook 13 G1 and its charger; here, it delivered the full 32W of the little HP charger.

Not connecting a charger to the hub is a common use case. This may happen for example when you’re giving a presentation and connect this hub to a beamer via HDMI. When you’re running off the battery, this is a great hub; we measured only 1.1W usage. Idle usage (i.e. hub connected to laptop, but no devices to the hub) only slightly below that: 0.7W. This is a bit more than what we’re used to with the VL318 chipset.

What happens when you overcurrent the ports of the hub? The behavior is actually different! The 0.9A port will first drop its voltage to 3.3V, then cut power. The 0.5A port will immediately cut power. At no point did it bring the laptop port in danger. Here’s a video of the test on the 0.9A port.

Ethernet port

We tested the ethernet port on both a 2016 MacBook Pro and a HP Chromebook 13 G1. In neither case, a driver is necessary; it just works out of the box which is very convenient. It identifies as a Realtek RTL8153.


This hub has two outputs; VGA and HDMI. As is usual with USB-C hubs, the HDMI port is limited to 30 Hz refresh rate when you use a 4K monitor. Although usable, we don’t recommend this for daily usage. When you don’t have a 4K monitor, the display is driven with 60 Hz. As noted in the specs, the resolution of the VGA port is limited to Full HD. We tested the video output from both a Chromebook and a MacBook Pro; everything works as expected.

Having a choice between video ports is very nice, especially if you live in the corporate world where some beamers still use a VGA connector.

Note that you have to choose between ports; you can’t drive multiple displays with this hub. This is noted in the specs.


The target audience for this hub is probably working in the office, regularly visiting clients to give presentations. Or alternatively, we see a market for laptop users who don’t want to spend a lot of money on a dock, and take a bit of extra time to neatly work away the somewhat messy cabling when you use all ports of this USB-C hub. This hub doesn’t offer an SD card slot or an audio jack.

As for alternatives, if you want more ports with better charging capabilities, we’d advise a dock like the CalDigit USB-C Dock. This will double the price, but comes with its own charger.

All in all, we’re very happy with this device. It delivers enough power, has plenty of ports and is robust and light-weight. For its price (around US$ 70 as of this writing), it’s an excellent purchase.

AUKEY CB-C55 on Amazon

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