[Official] U-NAS 8-bay Mini-ITX NAS (OTiS - 8th/9th gen Intel)

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This guide is an extension of the OTiS build guide. Basically, it’s an off-the-shelf NAS using (mostly) brand new parts, with the latest technology like Intel QuickSync and native NVMe support.

It’s centered around the U-NAS NSC-800 8-bay enclosure. It’s normally pretty expensive at $210 + shipping (without PSU!), but there’s quite a few available in brand new condition from an ebay seller for almost half that cost (with PSU!). Using the model off of ebay, I thought I’d throw together a modern NAS build and thoroughly document the process.

Currently, this guide will only cover hardware. I may add my experiences with Unraid and/or FreeNAS at a later time.

To navigate the thread, click on the sections on the right hand side.


I’ve always thought this chassis was super cool, but extremely overpriced. It retails for $200 + shipping, not including the $120 PSU, and $20 worth of cables and screws. Luckily, an ebay seller has a handful of these available with PSU included, for around $160 shipped - less than half the retail cost. That has me interested.

The Good

  • 8 hotswap SAS/SATA 3.5"/2.5" bays
  • Standard Mini-ITX motherboard support
  • Quiet 400W 80+ Gold PSU
  • Quiet 2x120mm fans
  • Outstanding quality, fit, and finish
  • Affordable and more powerful compared to other 8-bay off-the-shelf solutions

The Bad

  • A little tricky to work in
  • Need to replace cables for SAS support
  • No screws included
  • Mini-ITX motherboards are expensive and lacking features
  • Expensive compared to other 8-bay white-box NAS’s like the NAS Killer 4.0



If you have these handy, great! These are the tools that I used to complete this build.

Type Brand Part Notes Price (link)
Flashlight Streamlight Microstream Rechargeable $29.99
Tool Kit Oria Precision $12.99
Side Cutters Irwin Vise-Grip $9.49
Magnetic Tray JSBrothers Stainless $10.59

I highly recommend a magnetic screw tray and flashlight for this build. There are a ton of tiny screws that love to yeet themselves across the room if you look at them the wrong way. Also, your working space inside the chassis is very confined, so having a small flashlight (that isn’t your phone) helps out with that too.

Parts I used for this exact build

If you want to replicate my build exactly, these are the parts I used. If you’d like some substitution options, I’ll cover that in the next section below.

Please note that the U-NAS on ebay does not come with any mounting screws, so at minimum you need 3.5" and/or 2.5" HDD screws, as well as the motherboard and risers screws.

Type Brand Part Notes Price (link)
Case U-NAS NSC-800 Cheaper on ebay $128.99
PSU U-NAS 400W 80+ Gold incl. -----
CPU Intel i5-8500T $110.00
CPU Cooler Arctic Alpine 12 LP $9.99
Motherboard ASRock B365M-ITX $90.99
RAM TEAMGROUP 1x 16GB 2666MHz $45.99
HDD HGST 7K4000 SAS2 $48.00
SSD Gigabyte 1TB M.2 NVMe $109.99
SSD Heatsink Eluteng 2 pack 5% coupon $8.07
SAS HBA LSI 9207-8i after OBO $38.00
SAS Cable CableCreation 2xSFF-8087 breakout $14.99
PCIe Riser LEIHONG x8 to x16 10% coupon $8.98
Fans Arctic P12 PWM PST $30.00
Screws UXCELL #6 countersunk for 3.5" HDD $7.99
Screws UXCELL M3 countersunk for 2.5" SSD/HDD $8.49
Screws Honbay M3 truss for mobo + riser $5.99

Substitutions & Considerations


The PSU is perfect. It’s extremely quiet and very energy efficient. I don’t see a reason to replace it.


Take a look the CPU section for the OTiS build guide, as this one is based on that.

CPU Cooler

This is the only CPU cooler I’m aware of that will fit, and even it needs some modification. Be careful if you choose a different motherboard, as the socket position could be different than the one I have listed here, causing more interference.

With the i5-8500T and all 8 drives spinning, I’m seeing idle temps of around 37C. I do run the heat in our house, ambient temp is around 22C (71F).


It’s a NAS, so you can pretty much use whatever is cheapest. I linked the cheapest 16GB stick available at the time time of writing. If you want more, just double it up for 32GB.


I received these drives from bitdeals.tech (@BitDeals) specifically for this project, special shoutout to them for that.
Most of you will end up using WD shuckable HDDs, which are totally fine too.
Keep an eye on the vendor direct deals section as well.


Again, what SSD you use is really up to you and your specific needs. The motherboard supports 22110 length M.2 NVMe SSDs which opens up your options quite a bit. I would highly recommend using a heatsink for your NVMe drive (at minimum the controller) as airflow will be limited.

Check out these recent SSD deals and related threads:


The LSI 9207-8i is perfect for the job here. It comes with both brackets, it uses PCIe 3.0 for higher bandwidth, and supports both 4Kn and 512n drives. It’s also IT mode only, so it doesn’t need to be reflashed for Unraid, FreeNAS, and the like.

SAS Cables

Mildly angry rant with TLDR below.

Alright, this one’s a doozie. While the U-NAS NSC-800 is pre-wired with SFF-8087 breakout cables and has a SAS/SATA backplane, the cables themselves are not capable of carrying a SAS signal - only SATA. I could not get my SAS drives to spin up, no matter what I tried. The 3.3v mod is already taken care of because the backplanes are molex powered, so that wasn’t the issue. I tried SATA drives, and they worked. Odd. I swapped SAS HBAs, same effect. Tried removing the PCIe riser, same problem.

I looked at U-NAS’s site to see if they sold the cable directly, of course they don’t have any info on it. However, looking at the pictures, I spotted the part number printed on a label on the cable upside down. Typing the model “rms36-1908” resulted in this page, which of course had to be translated to english. And if you scroll down, what do you know… “In addition: Amphenol MINI SFF-8087 TO SATA3 x 4 silver-white cable body supports 6G black braided coating, only SATA interface SSD and hard disk can be connected for reference!” Bingo.

Who the fuck thought it was a good idea to make a SFF-8087 breakout cable only capable of SATA drives? Why would U-NAS use this cable when they explicitly state SAS & SATA compatibility, especially when the backplanes themselves have “SAS” printed on them? To make matters worse, U-NAS is charging $20 + shipping for a single one of these half-baked cables, when you can buy a pair of REAL SFF-8087 cables that are SAS AND SATA compatible for less than $15. Unbelievable.

TLDR: Buy new cables and throw the pre-wired ones in the trash. Even if you’re only using SATA drives, you’ll thank yourself later.


Just a bunch of packages! The U-NAS box is huge, definitely oversized.

Somehow the U-NAS was both simultaneously adequately and inadequately packaged.
The foam was tightly conformed to the U-NAS, but there was plenty of room for all of it to move around.

The front is metal, but covered in some sort of “soft touch” coating. It’s very odd. In pictures it looks like plastic, but it’s not. In person it’s feels very premium. I can imagine it would be hard to keep clean if you’re prone to skin cheese.

The ebay listing makes it look blue, but it’s not. It’s just black. Beneath the protective sticker is a black brushed piece of metal. It’ll look nice when it’s removed, but I’m going to wait until later to remove it.

Apparently, there are blue versions in the wild… I’ve yet to seen clear pictures of one.

There are 5 tiny black screws on the top panel that need to be removed in order to access the inside.

Pre-wired for SATA, Mini-ITX plastic sheet to protect the mobo from grounding, PSU included…

ASPOWER U1A-C20400-D 400W 80+ Gold PSU.

Front panel connector with USB 3.0. The front panel header on mine was a little bent on mine, but functioning.

Remove the drive sleds by depressing the small silver tab under the handle.

The drive sleds are vented and well made. I think they look pretty cool too.

The U-NAS has 2 4-bay direct passthrough backplanes which support SATA/SAS drives. Each backplane is molex powered, so no 3.3v mod necessary - it’s already done for you.

Motherboard Overview

ASRock B365M-ITX/ac
Download the manual now!

Single Intel GbE NIC, 2 DDR4 DIMM slots, 4 SATA ports, PCIe x16, M.2 NVMe 2280/22110 length support.

It also has Wireless AC built in, but most of us won’t use that.

Motherboard Assembly

The i5-8500T is an affordable low-power 6C CPU that also has Intel QuickSync. It’s pretty versatile and should perform well in a variety of applications.

Installing 12GB of RAM - 8GB and 4GB sticks. The 8GB stick is in slot A1, the 4GB in B1.

I’m using a 1TB 2280 length M.2 NVMe drive from Gigabyte. Not for any particular reason, it’s just what I had around. I would highly recommend installing a heatsink on your NVMe drive, because it won’t be getting much airflow.


Heatsink Installation

Arctic Alpine 12 with Gelid GC Extreme.

Even before attempting to install this into the U-NAS, it was pretty clear it was too tall. So I dug out an Intel stock HSF from a Pentium Gold.

Cleaned off the stock TIM, I’m at least going to Gelid this if I have to use a crappy cooler.

Much shorter… should be enough clearance.

Upgrading the Case Fans

Sorry U-NAS, I know better than you do. Gelid makes OK fans, but I’m going to use Arctic P12 PWM PST.

There are 8 screws to remove, 4 for each fan.

Turns out, even though the fans are completely unscrewed, you can’t remove the fans from the case. There just isn’t enough room.

There are 13 of these silver screws holding the black metal backplate onto the case. Remove these so we can get to the fans. Note that the 2 screws attached to the power supply are larger.

Don’t forget two on the sides…

And 3 on the bottom.

Back plate removed. It would have been easier for me to install the IO shield at this point.

Finally, I can remove these.

While we’re here, we have a good look at the HDD backplane. You can see there’s one physical SATA port for each drive, and 4 molex power connectors, 2 for each backplane. It was nice that it’s already pre-wired.

Arctic P12 PWM PST fans installed.

The wire is on the bottom, hopefully it makes cable management a little easier…

Connect the Front Panel

It won’t be possible to plug in your front panel with the motherboard installed, so now is a good time to do it.

More Heatsink Woes

This crossbar is in the way of a portion of the backplane. There are 4, removing one shouldn’t be an issue.

Looks like it fits…

Had to trim up a little more.

It still doesn’t quite fit. The motherboard will not mount up properly, as the backplane/cage is still making contact with the fan.

Arctic Alpine 12 LP

Finally, to the rescue - a properly sized CPU cooler.

It’s much shorter than even the Intel HSF.

I still had to do the same mod, clipping the fan brace. Again, 3/4 is plenty for this cooler. Just make sure you don’t clip the one with the fan power cable.

Motherboard + CPU Power Cables

Now is a good time to connect your 24-pin ATX power connector.

With the 24 pin installed, it’s now time to modify the 8-pin EPS cable.
As you can see, the motherboard standoff gets in the way of the EPS cable.

Remove the plastic retaining latches and reinstall the cable.
There’s plenty of room now!

Reinstall the Back Panel

Note where the fan wiring is being run.

Don’t forget, the PSU uses the 2 larger screws.

Plug the fan in behind the USB 3.0 connector. It’s a tight fit, a screwdriver and some finagling should help.

Install the PCIe Riser & SAS HBA

Lay out the riser, and plug it in.

My LSI 9207-8i came with both brackets, we’ll need to swap to the high profile bracket.

Screw down your riser with two screws, then install your LSI HBA.

I folded the extra riser length over the top.

Final Checks

Don’t forget to plug in the Molex connections for the backplane.

Make sure any and all wires are clear of the rear fans and the CPU HSF.
(a flashlight may help)

Drive Iinstallation

4TB HGST 7200 RPM SAS drives.

4 Supermicro-style drive sled screws are used on each drive. They have a bevel and sit flat when properly installed.

You can also use the bottom screw holes if you prefer.
There are native mounts for 2.5" SSD/HDD as well.

The right side (or bottom) has a plastic light pipe that shows power status and usage leds from the backplane.

Slide the drive in, label on the right.

Just reverse the process, and close the latch.

Here’s what a drive looks like installed into the backplane.


28+ lb with 8 drives installed.

All powered up!

Bonus 1: DAS Build

Want a dead simple 8-bay DAS? All you need is the U-NAS case, and a few parts.

Type Brand Part Notes Price (link)
Case U-NAS NSC-800 Cheaper on ebay $128.99
PSU U-NAS 400W 80+ Gold incl. -----
PSU Jumper Coolwin 24 pin $6.85
SAS Expander HP 24 drive 3Gbps $17.90
SAS Cable CableCreation SFF-8088 $14.99
PCIe Power UBit Minig Riser $9.98

Basically, you need the PSU to turn on when it receives power. The ATX jumper allows that to happen. The mining riser uses 4-pin molex to power the HP SAS expander. An external LSI SAS HBA in your main server will connect via SFF-8088 to your DAS’s external port on the HP SAS expander. The backplane inside the U-NAS is connected via SFF-8087 to the HP SAS expander.

Bonus 2: W-NAS

W-NAS = Double U-NAS

So, we’re going to combine the main NAS and DAS builds for a 16 bay build. Obviously, you’ll need 2 U-NAS NSC-800, and the parts for both builds.

The difference here is that you need a LSi 9207-4i4e card, instead of the usual LSI 9207-8i. We’ll be running 4 of the main NAS’s bays on the motherboard’s onboard SATA controller, and 4 from the “4i” (internal) portion of the SAS HBA. The “4e” (external) portion of the card will connect to the HP SAS expander of the DAS, for its 8 bays. The only downside to this is that 4 of the 16 bays will be SATA only, while the other 12 will be SATA or SAS.

Type Brand Part Notes Price (link)
SAS HBA LSI 9207-4i4e after OBO $38.00
SATA Cable Benfi 6 pack $7.99

@bashNinja also has a U-NAS build of his own, featuring NAS Killer 4.0 parts.


Unfortunately, mines not delivering until next week, gives me time to figure out my motherboard though :slight_smile:

The MSP I work for sells Datto backup appliances that use these cases. The build quality is solid. There is an almost rubberized feel to handle on the drive sleds that is nice. I’ve been wanting to buy one form the U-NAS store or from ebay but haven’t had much luck in finding a cheap, bare bones setup…until now. Thanks for the write up!

EDIT: SHIT! And they are gone. Lesson learned…buy before posting thank you here, derppp

EDIT EDIT: New link -

1 Like

Guide looks awesome, well done!

I did a similar build a few years ago now. Here’s my build list in case anyones interested in another build idea for the case. Opted for an ITX board with 8x sata ports, to free up the PCIE slot for a 10gbe nic :slight_smile:

Case: UNAS-800
CPU: Intel Pentium G4600T 35w tdp
Mobo: Asrock rack C236 WSI (ITX board with 8 sata ports & ECC support)
Ram: 16GB (2x Kingston ValueRAM 8GB ECC UDIMM KVR24E17S8/8)
PSU: Seasonic SS-350M1U
Cpu cooler: Noctua NH-L9I
Fans: 2x Noctua NF-S12A PWM
PCIE slot: Asus XG-C100C 10gbps NIC

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Thanks for sharing! I’m going to bother you for one more thing… have any pics? :slight_smile:

Can post some later in the week.

Something worth noting though, My case did require the 3.3v mod (taped over the pins) white label SATA drives taken from WD mybooks.

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Really? The backplane is Molex powered, there’s no 3.3v running to it. Is yours different?

Might be that the older cases weren’t - since mine is going on 2 years old now. Will check when I can and report back… All I can say for sure at the moment is the drives did not power up for me, without taping over the pins…

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How much power does it pull?

I may not have time to measure power output until Friday

Asrock rack C236 WSI is a pretty pricey motherboard (~$200) - but it does have 8 sata ports, so you free up the slot for 10gbe. Nice find on that for those that really want 10Gbe

That’s a shame that the C236 WSI is 6th/7th gen only as well. There are C246 versions that support 8th/9th gen, but they are even more expensive.

For those interested in 10Gb networking, there are a few options out there. These options below have 8 or more SATA ports onboard, leaving the PCIe slot free for a 10Gb card.

  1. ASRock C246 WSI
    • Supports 8th/9th gen Intel CPUs
    • 8 SATA onboard
      • 4 from OCuLink connector
        (use this cable)
  2. ASRock C236 WSI
    • Supports 6th/7th gen Intel CPUs
    • 8 SATA onboard
  3. ASRock C3557D4I-4L
    • Intel Atom C3558 CPU built in
    • 13 SATA onboard
      • 8 from mini SAS HD connectors
        (use this cable)

Ugh, out of stock again… Hopefully the seller has more.

Make sure to inspect your U-NAS right away when you get it. Looks like someone dropped mine or it was damaged before being shipped:

Oh no. That stinks

Thanks for the build guide, I grabbed one of the cases yesterday.

I’m guessing a i5-9600K @ 95w is going to be too much heat for this case right?

No, that should be fine. But that would be the maximum. Keep in mind the 95w is the max for the chip and you probably won’t be gaming on it.

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