ASUS PN51-S1 Mini PC with AMD Ryzen 7 5700U Review

Having run Project TinyMiniMicro for over two years now, one of the biggest requests we have gotten is looking at other PCs outside of the 1L options from Lenovo, HP, and Dell. One of the most requested is the small PCs from ASUS. It took until a few months ago for us to launch the STH Mini PC series, and so models have changed, but we decided to take the newest ASUS PN51-S1 for a spin. We purchased the highest-end AMD Ryzen 7 5700U version barebones and built a cool system out of it with 32GB of memory and 8TB of storage along with the 8-core CPU. This all fits in a very small package and so it was time for a review.

ASUS PN51-S1 Mini PC with AMD Ryzen 7 5700U Background

If you want to see the relative size compared to the Dell OptiPlex Micro 1L PC, that is in the first minute of the associated video. We also have noise testing live so you can hear the fan noise. This unit is fairly quiet, but also folks want to know the tone of fans, and so we wanted to show that as well.

As always, we suggest opening this in its own browser, tab, or app for the best viewing experience.

We purchased the unit for $529 a few weeks ago but it has dropped in price to under $500 at the time this piece is going live. We purchased the barebones AMD Ryzen 7 5700U version which is a low-power 8-core 16-thread processor. For those wondering about the AMD Ryzen 7 5800U and the ASRock 4×4, that is in the queue as well and we have numbers from that system in this review.

Here is an Amazon affiliate link (we may earn a small commission) to the unit we purchased. Pricing changes, so it is worth looking at what it currently is since we have seen a $70 swing while doing this article. There are also lower-cost options like the 5500U version that cost significantly less (e.g. >20% savings) but we wanted to test the higher-end unit.

We purchased the barebones unit with the intent to add memory and storage. We ended up adding quite a bit of both with 32GB of memory and an 8TB SSD. Many will know that William Harmon who did many reviews for STH over the years left for Sabrent and so I told him we would do a STH Mini PC system with his new products. The 8TB NVMe SSD in this form factor is quite crazy. We reviewed the unit in Sabrent Rocket Q 8TB Review Size Matters and the performance was virtually the same in this system. Also, the 2x 32GB DDR4-3200 SODIMMs worked without issue.

What this unit did not come with was a Windows 10 or Windows 11 license because it was barebones. Some of the listings for the PN51-S1-BB7000XTD make it sound like the system comes with

With that, let us get to the hardware.

ASUS PN51-S1 External Hardware Overview

This unit is small. It measures 115mm x 115mm x 49mm making it very small indeed. This is much smaller and lighter than the 1L PCs we look at as part of the Project TinyMiniMicro series.

On the front of the system we get a combo headset jack along with two USB 3 ports, one Type-C and one Type-A. There is also the power button and a HDD activity light. On the side of the system, we get what looks like an unlabeled Kennsington lock port.

On the other side, we just get vents. We will quickly note that the exterior of this unit is all plastic, but there is an internal metal structure. While the unit is light, the 1L corporate desktop PCs feel more substantial.

On the rear of the unit, we get a HDMI port as standard. There is then a DisplayPort that is in a configurable slot. Ours had the DisplayPort but this looks like something that ASUS can customize for corporate customers buying these in volume with other display outputs. There is a USB Type-C combo that one can drive a DisplayPort output through with an adapter. There are also two USB 3 Type-A ports and the DC input.

In the middle, one can see a RJ45 port. We have seen forum posts online saying this is 1GbE in this generation. We tested it both at 2.5GbE and 1GbE speeds, and while it runs at the slower 1GbE speeds, it is a 2.5GbE adapter and can run at 2.5Gbps. Here is a Ubuntu screenshot with the Realtek RTL8125:

The bottom of the unit has a nice regulatory marking label section as well as a vent. ASUS has mounting options for the unit, but perhaps the most important is that it has screws that are integrated with the rubber feet. Unscrewing those allows access to the interior of the chassis.

Next, let us get to our internal hardware overview and performance.