Micro PC added to the mini server rack for sandboxing

I’ve been watching for a good deal on a powerful micro PC for several weeks, so when this listing came up, I started bargaining: Dell OptiPlex 5090 Micro i7-10700T 32GB RAM 1TB NVME Win 11 Pro w/ AC Adapter.

The Dell OptiPlex 5090 is no longer available from Dell but I don’t consider it a legacy computer. It hasn’t been out of production for very long. The 5090 micro has the power and storage I was looking for, in a chassis that includes a USB-C port. I intend to use it primarily as a test bed for programs. This one is going in the mini-server rack. I already have a 3D-printed mount for it.

Micro PC arrived!

It took a week or so but the micro PC finally arrived. It looks almost pristine. There are some minor scuff marks but that’s about it. And as you’ll see in the interior photos, there is very little dust. Win.

First problem: the seller sent it locked with a password. Rather than go through the back-and-forth with the seller to get the password (and sometimes the seller doesn’t know what it is), I chose to reset the entire machine, downloading a fresh copy of Windows 11 Pro. That did take several hours but it’s worth it to me to know the machine is as clean as it can be.

Second problem: I couldn’t authenticate when remotely accessing the machine. Stated more clearly, my authentication kept failing. The solution that worked for me was to use the runas command in a terminal window. Bonus: this setting persisted after rebooting. Second bonus, this micro PC is pretty fast! The runas command format looks like this:

runas /user:"MicrosoftAccount\your_email@example.com" cmd.exe

I found great instructions at https://nready.net/remote-desktop-on-windows-11-with-microsoft-account-mfa/.

Interior photos

Let’s look under the hood.

In the image above, the front of the computer is to the right and the rear panel is to the left. The blue plastic piece is a tool-free carrier for a storage drive (and I note it is empty, so another drive might be in this PC’s future). The black plastic pieces near the top of the photo are the fan and ducting shroud.

Underneath the blue storage carrier is the 1 TB storage drive, shown near the bottom of the photo below. This is a full-size 2280 (22mm by 80 mm) drive.

Above and to the right of the M.2 storage drive is another M.2 connection for the installed wifi card. The SATA interface for the drive that can go into the blue carrier is just to the right of the round coin battery.

When removing the fan, there is a small clip on one end that captures a twisted pair of black wires. To get the fan out, you have to pop those wires out of the clip (and then remember to replace them when you reinstall the fan).

Looking underneath the black plastic cooling duct and the fan, we see a big heatsink for the i7 CPU and two sticks of RAM installed.

I had trouble getting an in-focus shot of the RAM sticks, but I think this image is clear enough to be legible. The RAM is PC4-2666V (DDR4 2666MHz SODIMM) non-ECC. Maximum capacity for this motherboard is 64 GB of RAM, so if I can find a deal on RAM — and given the escalating RAM prices, that will be quite a trick — I can bump the RAM up to 64 GB.

Performance

I installed 7-Zip and used the Benchmark tool to evaluate performance. Compared to the tests I did for the HP t630 thin client article, the Dell OptiPlex 5090 is astoundingly faster.

When I tested the HP t630 thin client, Dell Wyse 3040 thin client, and Raspberry Pi 4B, the ratings were in MIPS: Million Instructions Per Second. The Dell OptiPlex 5090 performance is in GIPS: Giga Instructions Per Second. Given that 1 GIPS = 1,000 MIPS, it’s easy to see that the 5090 has massively more raw processing power than those other machines. Verified: it’s a fast little beasty.

Desktop and programs

The desktop is very spare. I have Radiograph installed for basic performance monitoring. NetTime is also installed for time synchronization. I enabled the display of seconds in the taskbar clock and added a second clock for UTC time.

I also enabled Windows Sandbox, a simple virtualization/isolation tool. Says Microsoft:

Windows Sandbox (WSB) offers a lightweight, isolated desktop environment for safely running applications. It’s ideal for testing, debugging, exploring unknown files, and experimenting with tools. Applications installed within the sandbox remain isolated from the host machine using hypervisor-based virtualization. As a disposable virtual machine (VM), Windows Sandbox ensures reboot persistence, quick launch times, and a lower memory footprint compared to full VMs. Its one-click setup simplifies the user experience.

Here you see the Windows Sandbox running a desktop environment on top of the base Windows 11 Pro system.

I have the Dell OptiPlex 5090 micro PC installed in my server rack, running headless (i.e., without a monitor). Access is via RDP from my Windows 11 Pro laptop. Running it headless has worked well except when a system update is installed, and then I have to hook up a keyboard, mouse, and monitor to log back into the machine. Once that is done, I can disconnect those devices and log into the box remotely without issue.