While searching for as low-cost fan-less PC to use as a pfSense router we came across this unit on eBay. The Siemens SIMATIC IPC427C is an industrial PC that is completely fan-less and built to withstand extreme temperatures and the harsh environment of a factory or warehouse. They are often integrated into machinery and are responsible for control and monitoring. These units aren't PLCs, they are self-contained x86-64 computers capable of running Windows or Linux. They typically come installed with Windows Embedded XP or 7 on a compact flash card or internal SSD/HDD. This particular unit has an Intel Core 2 Duo CPU, 4gb of DDR3 RAM, and an 8gb CF card. Connections on the IPC427C include a 24V DC power input, DVI port, 4 USB 2.0 ports, serial port, PROFIBUS, and most importantly for pfSense: 2 Intel Gigabit Ethernet ports. Newer units such as the IPC427E even have DisplayPort and USB 3.0!

Getting pfSense to run on this unit was pretty simple. We erased the 8gb CF card, disabled UEFI boot in the BIOS setup utility and used a USB flash drive to install pfSense 2.6.0. Using the DVI connection resulted in some strange video behavior during setup so we opted to use a DVI to VGA adapter which completely solved this issue. The two Intel Gigabit NICs show up just fine in pfSense.

These devices are completely fan-less and passively cooled. As long as they aren't outfitted with a mechanical hard drive, there are zero moving parts! This makes them ideal for harsh industrial settings. The thick aluminum casing with built-in fins acts as a heat sink to dissipate heat passively.

The back panel can be removed to install a 2.5 inch HDD or SSD and also has a flip up cover in the corner to access the compact flash card.

Looking inside the unit, it's not far off from a typical embedded PC, but being a Siemens product we can expect high quality. On the top side is the CF card slot, a single DDR3 SODIMM memory slot, the power supply, and an expansion connector. The CPU is pressed against the heat sink casing on the reverse side along with the north/south bridge and other controllers.

Below is a screenshot of the IPC427C BIOS, which is from Insyde Software. It contains the typical x86 PC BIOS options but nothing too special. It does have UEFI which was disabled to better support pfSense on this particular unit.

Lastly, here is a screenshot of Windows XP Embedded that was originally installed on the CF card. It mostly just contained the default Siemens utilities for the IPC427C. Looking through the file system we were able to determine that this unit was likely responsible for controlling or monitoring some sort of solar electricity system.