Intel’s mobile-grade CPUs are typically found in NAS devices and entry-level mini-PCs. But there are a handful of SBC manufacturers that rely on x86 processors instead of ARM or RISC-V chips. If you're active in the SBC scene, you may recognize LattePanda and Odroid as developers of consumer-oriented x86 boards, though their offerings tend to cost a lot more than your average single-board computer.

However, Radxa’s latest SBC does things rather differently. Despite its affordable price, the Radxa X4 combines an x86 chip with the Raspberry Pi Foundation’s RP2040 microcontroller. As if this interesting combo wasn’t enough, the X4 includes 2.5GbE connectivity and enough RAM to run most operating systems with ease.

After reading the specs alone, you can imagine how excited I was about reviewing the Radxa X4. Having spent the past couple of days experimenting with the SBC, I’m happy to say that it lived up to all my expectations.

About this review: Radxa sent me the 8GB version of the X4 board along with its heatsink and an RTC module. But the company had zero input into the contents of the review.

Pricing, specs, and availability

Radxa announced the X4 back in July, and began accepting orders for the SBC in August. The cheapest version of the x86 board ships with 4GB LPDDR5 memory and costs $60, though you can upgrade to high-end models featuring more RAM and eMMC storage. As of writing, Arace Tech, AliExpress, and AllNet let you place international orders for the Radxa X4, though you may incur shipping fees on your purchase.

Design and ports

Plenty of connectivity options crammed into the sleek credit-card-sized form factor

At first glance, the Radxa X4 looks like your standard Raspberry Pi-inspired SBC. Featuring an all-green design with the same dimensions as most mainline Raspberry Pi boards, the Radxa X4 has the best port layout out of all SBCs in its price range. In addition to three high-speed USB 3.2 Gen 2 and one USB Gen 2 port, it includes one AUX jack, two micro HDMI connectors, and one 2.5GbE RJ45 port. Besides an (optional) external RTC module, the Radxa X4 also features Wi-Fi 6 and BT 5.2 U.FL connectors with the proper antennas for a solid all-round experience.

Keen-eyed readers may have noticed that the Radxa X4 doesn’t feature a SoC on top of the board. Once you flip the board over, you’ll find the Intel N100 CPU in all its x86 glory. Yup, unlike most SBCs, the X4 is powered by a full-fledged x86 processor, and it’s the same one you’d find on mini-PCs and portable NAS devices like the Aiffro K100.

Unlike most SBCs, the X4 is powered by a full-fledged x86 processor, and it’s the same one you’d find on mini-PCs and portable NAS devices.

The heatsink takes up a lot of space, though

However, you probably won’t (and shouldn’t) use the Radxa X4 without its heatsink. Although the case-cum-cooling solution does reduce the temps, you’ll have to mount the SBC upside-down on it. Since the bottom section of the case has two metal stands sticking out of it, you may run into some trouble when tightening the screws or attaching some accessories to the GPIO pins.

But the x86 CPU isn’t the only defining feature of the Radxa X4, as the 40-pin GPIO header on the SBC is powered by none other than an RP2040 microcontroller (which I’ll get to in a bit). For storage, the Radxa X4 comes with an M.2 M-key slot, where you can attach an NVMe 2230 SSD. Certain models also include an eMMC slot. Unfortunately, the Radxa X4 doesn’t come with a microSD card slot. That’s a major drawback for tinkerers like me who’d rather install multiple operating systems on different SD cards.

Software

It's compatible with multiple operating systems

One of my biggest issues with ARM-based SBCs is that they don’t support too many operating systems, at least when compared to those powered by x86 processors. Sure, the Raspberry Pi boards can run normal Linux distros like Ubuntu, Raspberry Pi OS, Kali Linux, and DietPi, in addition to LibreELEC, Recalbox, Nextcloud Pi, Home Assistant, and other specific-purpose operating systems. But there’s no denying that operating systems optimized for ARM chips often have limited functionality. Heck some, like Windows 11 and Proxmox, can’t be set up without subjecting your SBCs (and sanity) through long and complex installation procedures.

In stark contrast to 90% of its rivals, the Radxa X4 lets you install most x86 operating systems. If you’re used to installing operating systems on PCs, you won't have any issues setting up Windows 11 or your favorite Linux distro on the Radxa X4. All you have to do is plug a bootable USB drive into the device and use it to install the OS of your choice on the SBC.

If you’re used to installing operating systems on PCs, you won't have any issues setting up Windows 11 or your favorite Linux distro on the Radxa X4.

That said, Windows 11 does require some additional tweaks once you’ve installed it on an SSD. For some reason, the drivers for the iGPU, Ethernet, and GPIO pins are broken on a fresh installation of Microsoft’s flagship OS. Thankfully, Radxa provides official drivers on its website, and after a few restarts, your Radxa X4 will be able to run Windows 11 without any driver problems rearing their ugly heads.

Performance

The N100 processor can handle everyday tasks, including light gaming, on Windows 11

Although I was rather unimpressed by the N100’s virtualization prowess when running TrueNAS Scale on the Aiffro K100, the situation is a lot different when you’re using it for normal workloads on a $60 SBC. Using the Radxa X4 with a single 4K monitor provided a snappy experience for most tasks, including checking emails, opening multiple tabs on Chrome, and watching videos on YouTube. I also installed Obsidian, Greenshot, Lightroom, Blender, and a couple of other creativity tools on Windows 11. Aside from Photoshop and Illustrator tanking performance, most of the apps worked without any issues.

In addition to its rock-solid performance when running apps, the Radxa X4 has no issues streaming YouTube videos at 4K60FPS. Adding a second 2K monitor didn’t dampen the performance a lot on most apps, though I noticed some dropped frames when switching between fullscreen and windowed modes on YouTube alongside slight micro-stutters in Photoshop.

In addition to its rock-solid performance when running apps, the Radxa X4 has no issues streaming YouTube videos at 4K60FPS.

With the SBC performing beyond my expectations in everyday tasks, I just had to try running some games on it. Installing Steam was as painless as you’d imagine, and I kicked off the first round of tests by running my favorite 2D and non-demanding 2.5D/3D games at 1080p.

As expected, the Intel N100 and its iGPU began crawling at a snail’s pace once I booted up anything that could even remotely be considered taxing. None of the modern 3D titles in my library could break the 20 FPS barrier at 1280x720 resolution, even after setting all graphical settings to low.

With Armored Core VI: Fires of Rubicon and Elden Ring crashing minutes after launch, there was no point in testing the more resource-hogging titles. Although Cinebench showed rendering errors when I attempted to run the single and multicore tests, the results from the usual benchmark apps were what you’d expect from an underpowered CPU.

Linux distros work really well, and the RP2040 pulls its own weight when running MicroPython codes

Ubuntu, Elementary OS, and NixOS ran even better on the Radxa X4 than Windows 11. As someone who loves learning (and breaking) complex Linux distributions, I had no issues installing packages and compiling code inside NixOS.

Since we’re on the subject of programming, the RP2040 microcontroller is the one powering the 40-pin GPIO on the SBC. While you shouldn’t expect the same plug-in and play support from Raspberry Pi HATs, the RP2040 core can execute codes once you flash the necessary files. Using it is just as simple: pressing the BOOTSEL button under the Radxa label will cause the microcontroller to show up on the file manager as a USB storage drive, and you can copy the uf2 files over to it to begin executing your programs on the RP2040.

But there’s one essential metric that I haven’t discussed yet: thermals. And that’s because the sky-high temperatures on the Radxa X4 deserve an entire section of their own…

It’s the most thermally-challenged SBC I’ve ever used

When I reviewed the Raspberry Pi 5 last year, I wasn’t very impressed with the fact that it needed an active cooler. But as it turns out, the Radxa X4 has even bigger thermal issues than its rival. Attempting to install Windows 11 on an SSD without a proper cooler is just not plausible, as the N100 would overheat to the point where the built-in safety mechanism of the processor would power off the system in less than 15 minutes.

Adding the official heatsink/case somewhat alleviated the thermal issues... until I began testing the games. Running HWiNFO revealed the CPU would consistently remain at 75°C, which is well and good if the fan on the case wasn’t blasting at 100% speed. I was unable to find a tool that could help me reduce the fan speeds, so I’m not sure how well the case would hold up after months of use. Either way, the Radxa X4 is borderline unusable unless you drop an additional $15 on the official heatsink.

Should you buy the Radxa X4?

The Radxa X4 is worth every penny if:

• You want a powerful yet affordable alternative to the Raspberry Pi 5 with the same dimensions.
• You’re in the market for an x86 SBC that can run pretty much every desktop OS under the sun.
• You need a budget-friendly SBC that’s good for normal tasks and light 2D gaming.
• You want a device that can provide snappy performance even when running 4K monitors but don’t wish to shell over $200 on a mini-PC.

You shouldn’t buy the Radxa X4 if:

• You primarily use microSD cards and don’t want to spend extra on an M.2 2230 SSD.
• You want an SBC that doesn’t require a huge, $15 heatsink for even the lightest operations.
• You wish to interface HATs designed specifically for the Raspberry Pi.

There’s no denying that the Radxa X4 has a couple of flaws. Although the $60 price tag makes it a lot more mouth-watering than its x86 rivals, you’ll have to drop at least $75 on the SBC – assuming you already have an M.2 2230 SSD. Throw in the price of a cheap 256GB drive, and the effective price of the X4 spikes to $100. Plus, the case is rather awkwardly designed and makes the Radxa X4 a lot less compact than other Raspberry Pi SBCs.

Despite all the flaws, it’s still a worthwhile purchase for all tinkerers, regardless of whether you’re a newcomer wanting to learn the ropes, or a veteran with years of experience. Leaving aside the ability to interface sensors and run codes on the RP2040 MCU, the Intel N100, and LPDDR5 memory bring the Radxa X4 to the same playing field as most mini-PCs. The best part? For a mere $100, you’ll get a rock-solid SBC that can run most lightweight projects like a champ!