An old Samsung phone runs DeX on a monitor in my spare room, and it's the only computer that room needs

An old smartphone gets less attention than the primary one. After you replace it with a better one, the device seems to have no purpose left. My old Samsung Galaxy S21 FE also faded from the limelight and was reduced to infrequent YouTube sessions. However, I needed a spare computer in my room, and I didn't want to spend money on a new or refurbished one.

Samsung Galaxy phones support DeX mode, and I used it to convert an old monitor and phone into a usable PC. The setup required no manual tweaking or software add-ons, and it works over a single HDMI cable. It's cleaner than most PC setups and works well for web surfing and media playback. Let's discuss whether it's worth it to use a phone as a PC.

Not every room needs a powerful PC

A Samsung phone can work as one

It's ideal to have a powerful main system that handles your requirements. I have a laptop and external monitor setup that can run my preferred apps, games, and virtual machines without any problem. But for my other room, the hardware requirements aren't that high. I don't need a powerful laptop or desktop with additional peripherals. Even a normal computer with basic apps and a browser can fulfill my needs. It can also serve as an additional computer for kids for learning or entertainment.

An old phone like the Samsung Galaxy S21 FE doesn't have the power to run a full-fledged operating system. You cannot flash Windows or Linux on it and still use it as a regular PC. Samsung has been constantly working on DeX mode, a feature that makes the Android phone OS usable as a desktop. If you had asked me a few years back, I wouldn't have entertained the idea. But the company really improved DeX mode, and it now feels usable rather than like a barely working feature.

Since the DeX mode displays the phone UI on a bigger screen with desktop-like navigation, it doesn't need additional hardware for power. The phone's SoC handles everything, and at modest resolutions like HD and FHD, it doesn't seem like a compromise. But you need a few extra peripherals to build the setup.

Assembling the DeX PC setup

HDMI adapter, USB hubs, and a couple more things

The heart of this “PC” setup is an HDMI connection that enables the phone to display the UI on the desktop. Samsung DeX also has a wireless mode, but it's only useful on TVs that support it, and honestly, it can be painfully slow. I've tried it on my Sony TV and Xiaomi TV, and the inputs were noticeably slower. For a PC-like experience, I would prefer a cable connection. Since the phone lacks a mini-HDMI port, my best option is a USB-C to HDMI adapter.

It's not expensive, and at $5, there's really not much to ask for. It also includes an additional USB Type-C port and a USB Type-A port. The former is for connecting the phone charging cable to receive continuous power, and the bigger port can handle a USB hub. I need a USB hub because the setup is incomplete without a keyboard and mouse. So the hub is like an additional $3–5, but I used an old one.

Samsung DeX mode activates instantly when it detects a monitor connection. I didn't even need to open settings and turn on the mode for it to work. Wireless setup adds an extra step of scanning the device, but wired mode doesn't have any such restrictions. At first glance, things looked quite interesting.

Desktop experience on a phone

Better than my expectations

Samsung DeX mode gives you a familiar desktop feel and doesn't try to reinvent the UI. The desktop has few icons, a taskbar with a few pinned apps, and a system tray to control things like sound, network, notifications, etc. Any app that supports expanded mode looks almost like a real desktop app. I can add widgets, snap multiple open app windows to the left or right, and edit pinned icons.

You can use DeX at 1440p or 4K, but it needs a few extra tweaks. A Samsung Good Lock plugin called MultiStar enables high-resolution support and is especially useful for high-resolution setups. Browsers are the most used apps on any PC, and Chrome works great in DeX mode. Web surfing isn't a problem because the phone has ample memory to run multiple tabs without crashing. So, multitasking isn't a pain inside the browser, even with different button and icon positions.

You can watch YouTube in Chrome, but it's inferior to the native Android app experience. I can watch videos in small or expanded mode and access full media controls, which some apps lack. For an ad-free experience, you can use browsers that support ad-blocking extensions like Samsung Browser or Brave. I played videos at 720p, 1080p, and even 1440p, and they loaded fine. Bumping the playback speed didn't slow playback at all, and it’s a feature I absolutely need on a desktop.

I also tried a few other apps, like Google Docs, which is a primary part of my work. I wasn’t pleased with the UI, but it gives me a bigger screen and keyboard support, which is miles better than typing on the phone. For short edits, I would count it as a reliable app. I also use VLC for playing old anime stored on the phone, but it’s slightly inferior to YouTube’s playback experience. After you start playing, there are no on-screen controls, which can be a problem.

DeX uses your phone’s speakers for audio, but if you cannot bear the shrill sound, you can connect the phone to a Bluetooth soundbar, as I did. It elevates the movie and anime experience, making it much closer to a real desktop.

A spare PC without additional expenses

Repurposing a Samsung phone has almost no drawbacks. You can use the phone apps on your PC, and a few work just like their desktop counterparts. Samsung DeX is good for casual web browsing, light office work, and media playback. It needs about $10 for additional hardware, and you can multitask without hiccups. The only flaw is that you need to keep your phone plugged in, and it can get hot under heavy workloads.