How to connect the LG UltraFine 5K to Ethernet, USB, and more!

The LG UltraFine 5K display is a great panel in a drab box with only three 5 Gbps USB-C ports on the back. You can blame the enormous bandwidth taken up by the single Thunderbolt 3 port, which not only provides power to a MacBook Pro, but also transits 5K worth of pixels at 60 Hz. That sums up the problem. The solution, as you may have guessed, is dongles adapters.

Here's what I used to get the equivalent of my 2015 iMac connections back.

Note: USB-C accessories have been a mess over the last couple of years with a lot of inferior or just plain bad products hitting the market. I'm sticking to Apple adapters here — because they're certified and on sale at up to 50% off until March 31, 2017 — and a few cables from Amazon that are inexpensive but recommended by people I trust.


I prefer a hardline for my desktop internet. That's primarily because I do audio and video podcasting and Wi-Fi, as good as it has become, is still subject to interference and dropouts. So, if I can eliminate a potential point of failure, I'm going to do just that.

For that, on the LG UltraFine 5K, I need a USB-C to Ethernet adapter, namely, the Belkin USB-C to Gigabit Ethernet Adapter. They're hard to come by right now, so I'm actually daisy-chaining an older Ethernet adapter to USB-C like an animal, but I'll simplify as soon as this one comes in.

See at Amazon

Thunderbolt 2

"Luckily", it took forever for Thunderbolt 2 peripherals to come to market and when they did, they were expensive and I never saw much upside to them over USB 3 speed peripherals. So, I don't have any TB2 devices to plug in.

If you have big TB2 backup drives or similar, though, Apple makes a Thunderbolt 2 to USB C / Thunderbolt 3 dongle that works just fine. Well, just fine as long as 5 Gbps throughput is enough for you. Otherwise, you're better off getting the same dongle but plugging directly into one of the much faster TB3 ports on your MacBook Pro itself. It's more hassle, because you'll have to unplug and replug each time you want to use your laptop as a laptop, but sometimes speed beats convenience.

See at Apple


This is the big one. Everything from drives to printers, iPhones to the Magic Keyboards, Mouse, and TrackPad, connect over old-school USB, or USB-A. You need it to talk to or charge anything that's not wireless and not sold within the last year or two — oh, and many things still being sold today, like those aforementioned Apple products...

You have two options when it comes to converting USB-A to USB-C for the LG UltraFine 5K display. The more elegant is to re-purchase all your cables. Apple sells a USB-C to Lightning cable that can charge and transfer from iPhone or iPad, and can charge Magic Mouse 2, Magic Keyboard, Magic Trackpad 2, Siri Remote, and AirPods. I prefer the 1 meter version of desktop use but you can get 2 meters as well if it better fits your setup.

See at Apple

Similarly, you can get USB-C to USB-A cables if you want a nice, clean cord from your LG UltraFine 5K display to your wired printer, USB storage device, or other accessories. It's also super-handy if you just want to plug in a portable backup drive regularly and don't want to bother with adapters each time. In my case, I need them for the Logitech webcam and microphone I use for podcasting.

See at Amazon

You can even get USB-C to MicroUSB cables if you're in the habit of charging your Bluetooth or standard accessories, like headphones, game controllers, battery cases, power banks, from your desktop. I typically don't have the patience for it, so I plug them directly into a higher-power socket adapter, but the cable is there if you want it.

See at Amazon

A more multipurpose solution is, of course, a USB-A to USB-C adapter. If you're not plugging in a lot of USB-A accessories at the same time, it can save you money on new cables. Also, if you plan to travel or connect from home and work, you might find the dongles easier to pack and unpack on the go. Personally, I think it's a stopgap, but sometimes we have gaps that need stopping.

Apple has a version that's a short cable itself, which can be handy for getting into tight or overcrowded spaces.

See at Apple

Aukey also makes a USB-A to USB-C adapter that's more of a cap. It's smaller and easier to pack and travel with, so if it fits, use it.

See at Amazon

3.5mm jack

On my iMac, there's a 3.5mm headphone jack that I keep my podcast headphones plugged into. Switching to the LG UltraFine 5K, I lose that jack. (Insert iPhone 7 joke here.) There's still one on the MacBook Pro itself, of course. (Insert additional iPhone 7 joke here.) But I like the idea of plugging them into the display and just leaving them there.

Luckily, Apple sells a USB-C to 3.5mm jack. Yes, it sucks you need a dongle and iit requires on of the precious USB-C slots, but it works.

See at Apple

Your #DongleLife questions or suggestions?

If you have any questions about using your existing gear with your new LG UltraFine 5K display, let me know. And if you have any alternatives or suggestions, I'd love to hear them as well!

Rene Ritchie

Rene Ritchie is one of the most respected Apple analysts in the business, reaching a combined audience of over 40 million readers a month. His YouTube channel, Vector, has over 90 thousand subscribers and 14 million views and his podcasts, including Debug, have been downloaded over 20 million times. He also regularly co-hosts MacBreak Weekly for the TWiT network and co-hosted CES Live! and Talk Mobile. Based in Montreal, Rene is a former director of product marketing, web developer, and graphic designer. He's authored several books and appeared on numerous television and radio segments to discuss Apple and the technology industry. When not working, he likes to cook, grapple, and spend time with his friends and family.