A Closer Look

Unlike the 4X4 BOX units like the BOX-7735U/D5 among others, the NUC BOX-155H has a different external design. The top is smooth black plastic with a matte finish while the bottom is a matte black metal plate which has the four screws and feet along with two mounting holes for the VESA mount. While the finish does attract fingerprints it is not nearly as noticeable as the glossy black units I reviewed previously.


The Front I/O consists of a USB 3.2 Gen 2 Type-A port and 1x USB 3.2 Type-C port with support for DisplayPort 1.4a along with a USB4 / Thunderbolt 4 port that also supports DisplayPort 2.1. More importantly, the unit does offer eGPU support, which I can 100% confirm using my Akito Node Titan unit equipped with a pedestrian GeForce GTX 1650. This opens up the system to many new usage scenarios and even as a full-on gaming PC. Beyond the two USB4 ports, ASRock has opted to include a 3.5 mm microphone / headphone combo jack on the front as well. The power button is located on the front right. Meanwhile, the right side has a vented opening for cooling, although it is somewhat restricted, which may come into play later on.


Examining the back I/O, you'll discover a set of 2 USB 3.2 Gen 2 Type-A ports, 2x HDMI 2.1 TMDS ports, and 2x 2.5 GbE LAN ports, The power plug is also located here on the back along with a Kensington lock. While the system has a decent I/O array with excellent functionality, it does come with some limitations, as additional USB ports would require the use of a Type-C to Type-A hub or adapter. This means it falls short when compared to a full-fledged desktop, yet proves well-equipped when considering its compact size or in comparison to most slim and lightweight laptops. Like most of ASRock's Mini-PCs, this unit can handle up to four displays simultaneously and is equipped with Wi-Fi 6E and Bluetooth 5.3, thanks to the installed Intel AX211NGW module. Overall it is well-balanced for a Small Form Factor (SFF) system or Mini-PC.


To power the system, ASRock opted for an AcBel 120-watt power brick.