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


ASUS PN51-S1 Power Consumption and Noise

This unit came with a larger power brick and power consumption was relatively good in our configurations. On 120V power, we were in the 10-30W operating range for the system which is significantly lower than modern Project TinyMiniMicro systems.

ASUS PN51 S1 AMD Ryzen 7 5700U PSU
ASUS PN51 S1 AMD Ryzen 7 5700U PSU

This is one where we could see a PoE++ powered unit with an appropriate PoE splitter since it seems to be low enough power. PoE+ seems like it would be a little bit low in actual power delivery.

The noise on this system is very quiet at idle and light tasks. We ran a multi-core benchmark run on the video so you can hear it. These low-power U series processors are good for those worried about noise. It is not silent, but it is also far from loud or annoying.

Key Lessons Learned

This unit is very small. It makes a 1L PC look gargantuan. At the same time, it is a similar price to some of the other units we have looked at like the Minisforum HX90 and Beelink GTR5 GR9 once configured. If you are looking for all-out performance, or if you want more features like dual LAN, then going to one of those units is probably wiser. This is really focused on being very small, lightweight, and low power.

ASUS PN51 S1 AMD Ryzen 7 5700U Rear Ports
ASUS PN51 S1 AMD Ryzen 7 5700U Rear Ports

There are a few design elements we wish this had. Namely, a tool-less bottom cover, held in just by a latch instead of screws. Also, the tiny M.2 screws in this small chassis would be rough to recover, so we wish that ASUS just used a tool-less M.2 design for everything including the top HDD/SSD, the NVMe SSD, and perhaps the WiFi module. Even though the unit is plastic, it would have upgraded the experience of the barebones considerably.

ASUS PN51 S1 AMD Ryzen 7 5700U Under
ASUS PN51 S1 AMD Ryzen 7 5700U Under

Thanks to Sabrent for sending the 8TB SSD and memory so we could make something really interesting out of this system. A palm-size system having 8TB of storage, 32GB of memory, and an 8-core CPU is awesome. The unit can go up to 64GB, but that would be a bit much for the Ryzen 7 5700U.

ASUS PN51 S1 AMD Ryzen 7 5700U Internal With Sabrent 2x DDR4 3200 16GB SODIMMs And 1x 8TB Rocket Q NVMe
ASUS PN51 S1 AMD Ryzen 7 5700U Internal With Sabrent 2x DDR4 3200 16GB SODIMMs And 1x 8TB Rocket Q NVMe

One item we will probably try in the future is Velcro mounting the unit since it is so small and lightweight.

Final Words

Our perception of the ASUS PN51-S1 was likely dictated by just holding the unit. It is very lightweight and is quieter than many of the larger modern systems with higher TDP CPUs. This is not a perfect system, but for those looking for lower-power systems yet that still have a good amount of CPU resources and even 2.5GbE, this is a good option.

ASUS PN51 S1 AMD Ryzen 7 5700U Angle
ASUS PN51 S1 AMD Ryzen 7 5700U Angle

This is certainly a system we now understand why so many of our readers asked about, especially those who were looking for an Intel NUC-like alternative but with a Ryzen 5000 series CPU.

Design & Aesthetics
Feature Set
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Patrick has been running STH since 2009 and covers a wide variety of SME, SMB, and SOHO IT topics. Patrick is a consultant in the technology industry and has worked with numerous large hardware and storage vendors in the Silicon Valley. The goal of STH is simply to help users find some information about server, storage and networking, building blocks. If you have any helpful information please feel free to post on the forums.


  1. wouldn’t be bad to emphasize the name of processor “under scrutiny” with a different color (blue or inverted white on blue) in the graphs (especially those with two colors, like 7-zip compression)

  2. I have a couple of these running at the moment, one pn51-e1 with 5700u and one pn50 with 4500u, both with 32gb ram and upgraded Intel ax211 wifi6e cards (cheap drop in upgrade).
    They’re fantastic if you’re willing to pay the little bit more they ask.

    My only issue is windows 11 power management is completely broken (have to bypass it and use Asus own power app, or the old control panel power settings). AATU (apu tuning utility) works well on these if you need more or less power but the fan is not really adjustable and seems to only have a low, medium and high setting, no curve adjustment, no temperature threshold adjustment. So it always swings between dead silent and clearly audible under load at high power settings, no soft ramping of fan speed like other options. The 4500u is usually completely silent in normal office PC use. It’s mainly the 5700u that can get a bit annoying without severely restricting it’s power in AATU. If you let it breathe and wind it up to 40+w you can get benchmark results on par with a 2700X, but it will be screaming at you the whole time.

    I have an Akasa Turing A50 fanless case coming to test the 5700u in though. That should be fun to play with.

    I’d agree that the general miniPC home tinkerer should go with the minisforum or beelink options though

  3. Asus doesn’t issues security fixes for their PN series (too), therefore I don’t recommend this for business environment.
    I own a PN50-1S.

  4. Do you know if this supports ECC RAM? Would be nice to have this as a small server but in this form factor I can imagine the RAM getting toasty which ECC then becomes a saving grace.


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