Preface: how the COVID pandemic got me a new monitor

I think I don’t need to explain how the switch to WFH got me thinking about investing in a good monitor and a reasonably ergonomic work space at home. It affected my productivity big time when I had to switch from the full-sized keyboard and a 24” monitor holding two vim panes to a laptop keyboard and a 15” screen. But at the same time, I got used to a crisp hi-dpi Retina display of the work laptop.

The search for the perfect display got me here: Pixel Density Display Listing. From that chart, I decided that I need LG Ultrafine 4k with a 22-inch display, which is:

the highest PPI 4K monitor available,
is a reasonably-sized display and not a 27” monster like Ultrafine 5K,
doesn’t cost much nowadays as it was discontinued in favor of lower-ppi display.

So I ended up hunting for that display on Ebay and Facebook Marketplace and got my hands on it shortly after.

LG Ultrafine 4K is a great USB-C monitor

That’s all I want to say about the monitor itself – the resolution is great, it works well with USB-C laptops, and it has a Power Delivery feature which reduces cable clutter. The biggest downside is that it suffers from burn-out on edges, but that’s the trade-off I’m willing to accept.

Using Thunderbolt 2/mini-DisplayPort MBP with USB-C monitor

However, I got my personal old MacBook Pro (Early 2015) that I wanted to connect to the monitor as I occasionally use it too. This MBP’15 is equipped with Thunderbolt 2/mini-DisplayPort and HDMI outputs. The issue with HDMI out on this laptop is that it can only drive 4K at 30Hz, which is insufficient.

The problem is that the monitor is USB-C only, and doesn’t feature any other input ports. So I ended up looking for a TB2/mini-DP in, USB-C out cable or adapter, but couldn’t find it on Amazon or elsewhere. I ordered several combinations of cables but nothing worked.

Months later I was on a lookout for the solution and stumbled upon this comprehensive post in Dan S. Charlton’s Tech Blog: Bi-directional DisplayPort->USB-C, HDMI->USB-C, and HDMI->DP cables

The final combination that worked

Short AmazonBasics UTC-DP-B-L DP1.2 <–> USB-C cable
Cable Matters 8K Mini DP to DP 1.4 Adapter

Making it easy to switch laptops without replugging the monitor cable

And since the monitor’s input USB-C connector is so fragile, I didn’t want to plug and unplug cables every time when switching between laptops. The solution that I ended up with is to

keep USB-C to USB-C cable plugged in the monitor all the time,
when using USB-C mac, just use that cable,
when using TB2/mini-DP mac, attach Cellularize USB C Female to Female Adapter and then the final combo.

Hope this little note helps other users of this combination of monitor and laptops!