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Mini PC & Server

GMKtec M3 Mini PC Review: Good Home Server for VMware or Proxmox?

The GMKtec M3 Mini PC, also known as the mini PC NucBox M3, is a mini PC that I picked up on a Black Friday deal this year that I wanted to try out for the home lab and see if it would make a good candidate for running a home server on mini PCs hardware. This review is not sponsored, and I did purchase the M3 Nucbox with my own money, so the thoughts below are my own. Also, unlike other reviews, this review covers the potential of this mini PC to be used as a home server and is not focused on the typical use cases. So, keep that in mind. Let’s dive in.

Overview of the GMKtec Nucbox M3 Mini PC specs

Unlike some of the other GMKtec mini PC models with an AMD Ryzen processor (including the built-in Ryzen AI, etc), the M3 sports the Intel Alder Lake Core i5-12450H CPU with 8 cores and up to 12 threads with Smart Cache that will handle most tasks with virtualization just fine. Take a look at the hardware specifications in the table below.

SpecificationDetail
Processor12th Gen Intel Core i5-12450H, 8C/12T
Max Turbo Frequency4.4 GHz
Intel Smart Cache12 MB
TDP45W
GraphicsMax Dynamic Frequency up to 1.20 GHz, 48 execution units
RAMDDR4 3200 MT/s, SO-DIMM*2, max 64GB
StorageM.2 2280 PCIe 3.0, Up to 2TB, also has a 2242 SSD slot
Operating SystemWindows 11 Pro (installed), supports Linux
ConnectivityBT 5.2, WI-FI 6
USB PortsUSB3.2 (Gen1*1 5Gbps)3 + USB2.01
HDMIHDMI*2 4096 x 2160@60Hz
Type-CType-C (DP/DATA)*1
Audio3.5mm headphone jack*1
LAN2.5G Giga LAN (RJ45)*1 (Intel i225)
GMKtec M3 specifications

With the hardware specs above, including the GPU capabilities that you will see in the device manager in Windows, you won’t be able to play the latest games with the M3 or do super fast processing, but it will likely do fine with mid-range game titles for a decent experience. In addition to Windows 11, it will also be a good productivity machine with WiFi, used for web browsing.

Ports and Connectivity

As you can see in the table above it has multiple USB ports, a USB Type-C port, dual HDMI outputs, Bluetooth 5.2, and Wi-Fi 6.

Gaming and Multimedia

The GMKtec M3 can be a gaming PC for casual gamers. It has integrated graphics that are not as powerful as true dedicated gaming machines, but it offers enough power for many popular titles. It can definitely be used for video streaming and photo editing as well.

Operating System

Pre-installed with Windows 11 Pro, the NucBox M3 also supports Linux. This allows for options in what you want to run in terms of OS. The Pro license with Windows 11 will also afford the ability to run Hyper-V if you want to have this as a daily driver along with a hypervisor host for some labbing.

Windows 11 pro edition is installed on the gmktec m3
Windows 11 pro edition is installed on the gmktec m3
It comes with windows 11 22h2 preinstalled
It comes with windows 11 22h2 preinstalled

Expansion and Upgrade Potential

The GMKtec M3 does have upgrade potential. One thing I like is that it comes with an additional 2242 SSD slot that can be populated for additional storage.

Unboxing the GMKtec M3 Mini PC

Below is the unboxing of the GMKtec M3 Mini PC. As the other PCs I have reviewed from GMKtec, the packaging is of high quality and nice overall and mounts for a wall or back of a monitor. The version I purchased came with  with a 1TB drive from GMK and I got a good price with Black Friday deals.

Gmktek m3 in the box
Gmktec m3 in the box

After pulling the top lid from the GMKtec M3 box.

Lid off the box with the gmktec m3
Lid off the box with the gmktec m3

Looking at the front side of the M3, it really looks a lot like a Nuc. On this side, it has (2) USB-A ports and the power button. It has a solid build quality with attention to detail and no ports on the sides, but only the rear.

Viewing the front ports
Viewing the front ports

Swinging around to the back side of the M3, this is the business end of the mini PC with the power barrel connection, audio jack, HDMI ports, 2.5 Gbps LAN port, (2) more USB-A ports, and a USB-C port. As you can see, there are no Displayport 1.4 ports.

Viewing the rear io ports on the gmktec m3
Viewing the rear io ports on the gmktec m3

You can easily access the RAM and storage of the devices by taking out the (4) screws on the underneath side where the rubber feet are. Here you can see the included PCI-e 1TB drive. Keep in mind this is not PCIE 4.0, only 3.0. I quickly swapped this out for an NVMe SSD for installing hypervisors. You can also see the DDR-4 RAM SODIMM slots in the form of (2) 16GB

Viewing the internal ram and storage
Viewing the internal ram and storage

Hypervisors

Thanks to its Intel i225 2.5 Gbps network adapter, at least on paper, the GMKtek M3 can run both VMware vSphere and Linux-based hypervisors, like Proxmox, XCP-ng, and KVM, among others. I would like for you guys to know which mini PCs I review have Intel-based network adapters, as I believe this adds to its value as a home server.

Options equal value in my opinion. If you have a mini PC that is capable of running multiple hypervisors, it gives yo the ability to switch in the future if you want to play around with something different/new. If you only have a network adapter that will work with Proxmox and not VMware ESXi, you will want to keep this in mind.

It is great to see this model use the Intel-based network adapter and not a Realtek-based adapter like many of the mini PCs. However, it does seem to be more common to see the models equipped with Intel processors also have Intel-based network adapters, while AMD models often sport Realtek cards.

After seeing the agreeable specs to run both VMware and Proxmox, this is when I ran into a few issues as I will detail below.

Challenge with VMware ESXi on the GMKtec M3

Vmware vsphere
Vmware vsphere

If you want to use this mini PC for loading ESXi as your home server hypervisor, there is a bug affecting 12th and 13th generation Intel CPUs that will result in the Purple Screen of Death (PSoD) in ESXi.

Purple screen of death due to the e cores and p cores on the alder lake processor
Purple screen of death due to the e cores and p cores on the alder lake processor

There is a workaround with this issue though. When the VMware ESXi installer is booting, you can press SHIFT+O when prompted to do so and enter the following boot kernel option:

cpuUniformityHardCheckPanic=FALSE

Install VMware ESXi, and when it boots again from the install, go through the same process to enter the boot configuration parameter.

After you have booted into VMware ESXi, you can then make this permanent with the following command:

esxcli system settings kernel set -s cpuUniformityHardCheckPanic -v FALSE

Other than this issue with the newer Intel Core i5 processor, it works great for VMware ESXi from a networking perspective.

The Intel 2.5 Gbps ethernet port adapter is detected and works fine in VMware ESXi 8.0 Update 2.

Viewing the network adapter in esxi
Viewing the network adapter in esxi

You will also see the TPM warning in VMware ESXi as you will see from most of the mini PCs that have TPMs installed. This is due to the type of TPM and the way they work compared to what ESXi expects.

Tpm warning on the m3
Tpm warning on the m3

Challenges with Proxmox installation

Generally, it is VMware ESXi that I have challenges with installing on mini PCs, due to network connectivity, etc. However, this mini PC presented an interesting issue I haven’t seen before with Proxmox, but it looks like one that has seen some forum posts.

Proxmox ve
Proxmox ve

When installing Proxmox 8, the M3 powers off during the installation. I tried both an 8.0.2 ISO and an 8.1.3 ISO and both presented with the same issue.

However, it looks like Proxmox 7.4.1 installs without any issues with the mini PC powering off. However, once it finishes installing and then reboots, it powers off for me as well. This is definitely an odd one and is documented here, on the official Proxmox forums: Proxmox host shuts down when trying to install Proxmox 8?.

Noise profile

The GMKtec M3 is a quiet mini PC. Even with the internal fan, it was not very loud at all when used as a home server. Compared to enterprise server hardware and even the IoT servers I am used to running in the home lab, the M3 is extremely quiet.

Power consumption

What is the power consumption of the box? The GMKtec M3 is less power efficient with the i5-12450H processor, compared to other processors like the Ryzen 5700U (found in laptops) I reviewed in the GMKtec Nucbox K10.

Below is a shot of the power consumption as the machine was booted and idling with NO VMs.

Power consumption of the gmktec m3
Power consumption of the gmktec m3

Comparing this with the GMKtec K10

All in all, I like the M3 if you are looking for an Intel mini PC. However, I think it is quite as good from a value standpoint as the GMKtec K10 that I reviewed. The reason is the 5800U processor is much more power efficient than the Core i5 12450H processor in this unit, and the performance is just a notch under the 5800U.

As you can see below, the 5800U is more desirable in just about every area, even though it isn’t as new as the Core i5-12450H.

  • The 5800U has more threads (16 compared to 12)
  • It is more power efficient (15W vs 45W)
  • The CPU mark score is better (18620 vs 17494) on the benchmarks
Cpumarks comparing the ryzen 5800u and the core i5 12450h processors
Cpumarks comparing the ryzen 5800u and the core i5 12450h processors

Check out my video below of the GMKtec Nucbox K10:

Pricing and Value

The GMKtec M3 is affordable and performs well with the Core i5-12450H processor. With the dual-channel DDR4 memory and the extra 2242 SSD slot, you can expand your memory and storage capabilities.

However, I do think there are better mini PC models out there for a home server. I like the GMKtec K10 better as a home server since it has a much more power-efficient 5800U processor with more threads and the same max memory configuration.

The M3 does have an edge on the K10 in terms of storage expandability since it has the extra SSD slot that you don’t have in the K10.

You can also buy the M3 currently on Amazon for $399 with a $90 coupon. The K10 is around $429 with no coupon at this time.

Frequently Asked Questions

Is the GMKtek M3 suitable for high-end gaming?

The Intel Core i5 and UHD graphics of the M3 can handle casual gaming and some modern games at low settings. It is not recommended for high-end gaming.

Can I upgrade the RAM and storage in the future?

The GMKtek M3 offers 2 RAM slots for memory upgrades. It supports up to 64GB DDR4 RAM and M.2 2280 PCIe 3.0 SSD and 1 2242 SSD.

Does it support dual monitors (multiple displays)?

Yes it has dual HDMI ports capable of supporting two monitors at 4096 x 2160 resolution at 60Hz.

How does the GMKtek M3 perform for creative tasks like photo and video editing?

The GMKtek M3 can handle photo and video editing tasks for most users. However, it does not have a discrete graphics card like an nVIDIA or AMD chip that most would want to have for a dedicated photo and video editing machine. 

Is the GMKtek M3 a good choice for a home server?

In my testing, there were too many issues getting common hypervisors to run, like VMware vSphere and Proxmox. I would not recommend it for a home server and there are better models available like the GMKtec K10.

Can I run Linux on the GMKtek M3?

The GMKtek M3 supports Linux, in addition to Windows 11 Pro which comes preinstalled.

What WiFi is supported on the M3?

It is equipped with Wi-Fi 6 which helps to future-proof its wireless capabilities.

What are the USB connectivity options available?

The GMKtek M3 comes with several USB ports. These include three USB 3.2 Gen 1 ports and one USB 2.0 port.

Wrapping up the features of the GMKtec M3 as a home server

The GMKtec M3 is a good option for those seeking an efficient desktop replacement. However, I would not recommend it for a home server. There seem to be too many weird issues with running hypervisors, including VMware ESXi and Proxmox. The Proxmox issue is the most perplexing. I will keep you guys posted if I see anything further on this one. As explained, I was able to get VMware ESXi on the M3 by adding the kernel boot command during installation and then on the first boot. You can make that persistent with the command given above. However, I really like the other Ryzen chip mini PC configurations like the k10, as these are less finicky than the E-cores and P-cores configurations for a home server.

Brandon Lee

Brandon Lee is the Senior Writer, Engineer and owner at Virtualizationhowto.com and has over two decades of experience in Information Technology. Having worked for numerous Fortune 500 companies as well as in various industries, Brandon has extensive experience in various IT segments and is a strong advocate for open source technologies. Brandon holds many industry certifications, loves the outdoors and spending time with family.

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