Small-form factor PCs tend to lack features, underperform, and cost a fortune. The Minisforum U850 NUC-sized mini-PC breaks all three rules, delivering a NUC-killing mini-PC for $599. The U850 suffers from a couple of Achilles Heels but its virtues make up for it.

What Is Minisforum?

Minisforum designs a range of small-form-factor computers. Their products get as small as stick-PCs and scale up to NUC-sized computers. They use processors from both AMD and Intel. Most of their computers include the option to upgrade individual components. For example, the U850's RAM can scale up to 64GB and its SSD can go up to 500GB.

Hardware Analysis

To the extent of my knowledge of small, NUC-sized computers, no similarly-sized mini-PC offers the same level of features as the U850. For example, it's common among mini-PCs to cripple integrated graphics with a single SO-DIMM RAM slot. And, at best, you might find a single 2.5-drive bay. Worst of all, the processors usually use a 15-watt wattage limitation and perform like laptops.

The hardware on the Minisforum U850 beats down its NUC-class competition. The U850 may use laptop-class components, but the processor has been configured to run at 25 watts, instead of the lower 15 watts. As far as low-wattage, quadcore, eight-thread processors go, it's performant, snappy, and can handle pretty much any home computing scenario thrown at it.

Specifications and Hardware for Base Model U850

• CPU: Intel Comet Lake 14nm 10210U cTDP: 25-watts
• GPU: Intel UHD 630
• RAM: 16GB DDR4
• Storage: 256GB Kingston Design-In NVMe SSD
• Operating System: Windows 10 Pro
• Dimensions: 127 x 127 x 53.1mm
• Wattage consumption: 35-watts maximum; 0.5-watts idle; 13.5-watts average
• Power adapter: 65-watt USB-C power adapter
• Cost: $599
• Video: DisplayPort and HDMI 2.0
• Ports: 4x USB-A 3.1, 1GB LAN, 2.5GB LAN, USB-C 3.1, 3.5mm
• Security: Kensington lock port
• Wireless: Bluetooth 5.1, Wi-Fi 6 (802.11ax)
• Other: VESA mounting bracket, 100 x 100mm
• Weight: 500 grams

Who Is the Minisforum U850 Mini-PC for?

The Minisforum U850 is for Small Form Factor (SFF) enthusiasts who feel dissatisfied with the lack of flexibility in NUC-sized computers. Anyone interested in an Intel NUC needs to take a close look at the U850 because chances are, the U850 will meet your needs for less money.

I don't see any reason to spend more money on a NUC when the U850 is better in every way I could conceive of, except one: the U850 cannot refresh a 4K panel on its HDMI port at 60Hz.

RAID1 and Dual LAN in a Mini-PC

If you want to squeeze the most utility out of the U850's hardware, the two features that jump out are the dual LAN and the dual SATA ports. The dual LAN ports allow it to bridge two network connections, function as a repeater while hooked up to a NAS, and a lot more (the vast majority of PC users will never touch a dual LAN port, by the way).

The dual SATA slots let you use a feature known as Redundant Array of Independent Disks. There are several types of RAID configurations; RAID1 allows for any single drive to fail, without it destroying any data.

Related: What is RAID, and can I use it on my PC?

The U850's ideal usage scenario is probably in an enterprise role, where it would allow two different networks access to a RAID1 network drive. However, it has a lot of other uses aside from enterprise and someone with greater IT experience than I could probably write a book on it.

It's NUC-Sized and VESA Mountable

The U850 is for folks who want a tiny computer. The 127 x 127 x 53.1mm dimensions make it's less than half the size of an ITX PC. As an added bonus, Minisforum includes a VESA-mounting bracket, which lets you screw it onto the back on a television or monitor. Overall, the U850 is designed for keeping your desk clear of a bulky computer and wires.

Good, But Loud Cooling

But with an extra 10-watts of power to dissipate, something had to give. Fortunately, Minisforum chose to beef up the cooling, as well. The fan inside of the U850 is significantly larger than cooling solutions you'd find in a laptop, although still tiny compared to large-sized ATX coolers used in tower PCs.

To test cooling, I disabled all power-saving features using the excellent Throttlestop software. Then I hit the processor with a variety of CPU loads. I'm happy to say that stress testing didn't lead to any CPU overheats. However, even with BD PROCHOT disabled, I could not stop the processor from throttling down to 2GHz.

On the downside, under full load, the cooler can hit 48 decibels, which is moderately loud.

Easy Disassembly

The U850's chassis is designed for disassembly. It's the easiest computer that I've ever torn down. Accessing the inner components just requires pressing down on the lower-left and right sides of the plastic top cover. Removing the top exposes all of the modular components, with the exception of the CPU, which isn't modular.

All of the parts use standard mounting mechanisms and can be swapped out or replaced as easily as with any ATX-sized component. However, Minisforum chose to hot glue the SMA connectors on the Wi-Fi card, which required a little effort to remove.

Energy Efficiency

An advantage of using laptop components is that you get laptop-like efficiency. The overall power footprint of the U850 (with a RAID1 setup) comes in at 35-watts at maximum loads, 13.5-watts at average loads, and 0.5-watts while in suspension.

Benchmarks and Performance

Synthetic benchmarks aren't very accurate and exist for making loose comparisons between processors. More or less, the Comet Lake Core i5-10210U inside offers a significant performance improvement over Intel's older Kaby Lake-R chips, but it's not quite on par with the latest AMD Ryzen mobile processors, even it's still competitive with them.

On the other hand, the Intel UHD 630 is by no means a solid integrated GPU. At best it can play older games at 1080p, with playable frame rates. As mentioned earlier, the U850's design focuses on low-power consumption and not performance. Definitely not gaming performance.

Kingston Design-In SSD: Benchmark and Performance

The 256GB Kingston Design-In SSD (model #OM8PDP3256B-A01) inside of the U850 includes NVMe 1.3, an SLC cache, 3D TLC NAND, and a Phison controller (model# PHA-PS5013-E13-31). In other words, it's a budget-class, DRAM-less drive. While not as performant as Samsung's high-end segment, it's a solid drive.

Kingston's Design-In product line tailors to manufacturers, not customers. As a result, they don't hand out very many firmware updates. So if any bugs show up down the line, it's up to Minisforum to push out the firmware update, not Kingston.

Kingston does provide a three-year warranty on its drives, which is unusual for OEM-supplied components. Unfortunately, like most SSD warranties, the warranty expires if you write too much data to the drive or three years elapse, whichever comes first.

I wish that Minisforum would sell a barebones version of their U850, which would allow you to throw in a DRAM-equipped SSD. But even with a lower-tier drive, the U850 still offers better value compared to NUCs.

Performance CPU and GPU

I used PassMark's bench-test software to test the Intel Core i5-10210U processor. PassMark isn't the most accurate of tests, but it does a good job of determining the relative performance of a processor.

PassMark gave the CPU a score of 7005.6 putting it roughly 20% ahead of the Kaby Lake-R mobile processor inside of my laptop. Despite Intel using the same basic 14nm technology node, the Core i5-10210U is still competitive with other mobile processors, possibly because the U850 increases its TDP to 25-watts.

Again, PassMark's scoring system doesn't mean that the U850 offers 20% greater speed. It's just 20% faster on a synthetic benchmark. The Jetstream 2 benchmark shows a similar performance difference.

Minisform U850 RAID1 With 2x 2.5-Inch HDDs

I can confirm that RAID1 works and performs as it should with two 2.5-inch hard disc drives (HDD) attached. The U850 doesn't include any special RAID levels. You must choose between using the drives as just a bunch of disks (JBOD) or as a mirrored array, in which you get half the storage capacity in exchange for redundancy.

The bottom drive usually hovered around 33-34C with the top drive hitting 32-33C. Running a sustained transfer, the real-world file-transfer speeds for writes hit 85MB/s and reads at 50MB/s. The drives reached 53 and 55C respectively after 30 minutes and both were at 60C after 1 hour of sustained transfer, which is far outside of a platter-based HDD's operating temperatures.

Most HDDs have a maximum operating temperature of 50C. Given that operating a computer component well over its design threshold is a disaster waiting to happen, I'd recommend using SSDs instead of HDDs, which can safely run at up to 70C.

RAID1 Benchmark

The synthetic benchmark speeds are approximately equal to the maximum speeds offered by 5400RPM HDD drives. In other words, there doesn't appear to be any significant bottleneck in the U850 for managing two SATA drives in a RAID1 array.

CPU Temperatures

SFF computers pack a lot of hardware into as tiny a space as possible. Unfortunately, that oftentimes means higher temperatures for internal components. Higher component temperatures can spell an early doom for the most sensitive components of a computer by prematurely aging silicon.

The U850, however, throttles its CPU frequency at around 85C. You shouldn't experience any issues with CPU temperature, even with heavy workloads.

Drive Temperatures Under CPU Load

The U850 does not use direct cooling on its drive bay. That means sustained writes to the drives will result in overheating. However, a question you might have is whether or not a high-CPU load will overheat the 2.5-inch drives. In short, heavy CPU loads won't overheat the 2.5-inch drives.

I ran the HDD drives up to 50C and 47C respectively and then blasted the processor with a sustained Prime95 torture test, which generates a lot of heat. As you can see from the graph above, as the CPU fan increased in speed, the 2.5-inch drives decreased in temperature. While the air circulation from the heat-sink fan assembly does not touch the drive bay, it does somehow manage to reduce the temperatures.

Drive temperatures did slowly creep up over time, but they eventually leveled off well below their maximum operating temperature.

Linux Compatibility

While its mainboard is compatible with Ubuntu Linux 18.04 LTS and 20.04 LTS, the U850's Intel AX200 Wi-Fi 6 network card won't work out-the-box with either version.

However, even though the BIOS/UEFI settings aren't accessible, Intel's VT-d setting is turned on by default (although not accessible) so running Linux virtual machines isn't a problem.

The Minisforum U850 Problems

The U850 isn't perfect.

HDD Drives May Overheat

As mentioned earlier, long file transfers cause the 2.5-inch drives to overheat, hitting 60C after an hour of sustained transfer; this means you either need two SSDs in a RAID1 configuration or you should avoid using HDD drives for sustained transfers.

Windows 10 Recovery Partition Does Work

A big potential issue is that the recovery partition doesn't work. I'm not sure whether this is a problem with the unit I tested or whether something went wrong at the manufacturing facility. But if you need to boot from the recovery partition, it might not work. However, you can always create your own bootable Windows 10 recovery drive.

Intel AX200 Wireless Adapter Doesn't Automatically Work With Linux

The Intel AX200 Wi-Fi adapter is not, out-of-the-box compatible with Linux (of any kind that I could find) and requires a lot of additional work to get functional.

Custom Drivers Not Available Online

Because of the dysfunctional recovery partition, if you ever reset the computer, you'll need to acquire the drives somehow. And, unfortunately, the firmware and drivers were not made available online at the time of review.

You can email Minisforum's customer support, though. They respond to inquiries, usually, within 24-hours. But they have yet to respond to my last request for support.

Can't Change BIOS/UEFI Settings

The BIOS settings available are limited to setting an administrator password or changing the boot medium. It's not possible to change very many settings, including configurable TDP.

No 60Hz at 4K Resolutions on HDMI Port

The U850's Intel UHD 630 does not do 4K at 60Hz over HDMI. It can do 4K over DisplayPort at 60Hz, however.

No Thunderbolt 3

The USB Type-C (USB-C) port doesn't offer Thunderbolt 3 compatibility, which limits its transfer speed to 2.5GB/second. Thunderbolt 3 would have doubled the transfer speeds.

Should You Buy the Minisforum U850 Mini-PC?

The Minisforum U850 offers a similar size as a NUC but with a much wider range of uses and much higher value. While it's expensive, particularly compared to a laptop or desktop computer, it's also versatile and packed to the heat vents with features.

To my knowledge, there's no better-priced NUC, or NUC-like computer, out there. If you love small form factor computers, or just need to economize on desk space, the U850 is worth checking out. But for those who want a more performant computer, you can get a much better deal by buying a full-sized desktop.