Log SMALLEST ATX CASE : CERBERUS-X (Complete build log)

[MarcParis]

Well, "only 1 gen5" doesnt sound too bad, because cooling of Gen 5 m2 is such a big PITA alreay. But the implementation of the 3x m2 design feels rather .. loveless and disinterested. Like: "Well, we did say we gotta do this for AM5 a year ago, but .. ugh, do we really HAVE to do this? What, bossman says we have to? Oh man! Yeah, whatever."

I'm currently looking more into mATX again, as there seem to be quite a few good options with similar specs, but less tradeoffs.

What I still find to be harsh irony is: USB4 seems to be almost exclusive to ATX boards - considering the fact that this type of IO would be much more useful for ITX and small form factor ..

cu, w0lf.

About Gen 5 m.2 drives I would agree about their excessive heat generation for the 1st models...till 2024. Recent models (9100 Pro, SN8100) are WAY better, cutting almost by 2 the power consumption versus early generation. I would say that Gen 5 mainstream time has just started.
USB4, for AMD, remains a niche feature...as you mentionned, mostly focused on ATX and very few mini ITX MB. On Intel 200, it is mainstream as the USB4 controller is embedded inside the CPU directly. It is expected that AMD will follow this thread on Zen 6+ generation with compatible motherboard.

On that mATX topic: Have you seen this one? Asus Rog Strix B850-G Gaming Wifi - comes with FOUR m2 slots, and none of them are like half-hearted 2x. They repurposed the additional PCIe slot to achieve this, but at the end of the day, one probably could just use an adapter if one really required that particular slot for extension cards, eg. the one on the back.

cu, w0lf.

Related to micro ATX motherboard, you are right, there is high potential...but that is the not the market trend. I was on MATX back to 2008 then moved to mini ITX then back to ATX (since Zen). MATX is blocked between the ATX & Mini ITX form factor. Customers that want best size will pick up Mini ITX. Customers that wants full features will pick ATX.
On top of that MATX cases are not so smaller compared to ATX. First, ATX MB cases starts around 15L-23L ...a similar size to MATX...whereas Mini ITX can squeeze till 7L with a dedicated GPU.
At last, MATX motherboards are not great, either in terms of choice or features. The Asus Rog Strix B850-G is pretty nice, but no USB4, no offset of the 1st PCIe port (like on ATX), gen 4 m2 (except the only connected), no bifurcation. The ATX Asus B850E strix is beating it by far...but it is bigger and more expensive. The current MATX trend is to go to cost efficiency market...but the mini ITX & especially ATX are also doing the same.

 

[milesvw]

How would a Jiushark JF13K Diamond fit?

 

[hrh_ginsterbusch]

Smallest mATX I know is 5L. True, it only works as APU with either external brick or AC/DC adapter stuff, but it's totally doable. More approachable options sit between 7 and 10L, allowing for LP GPUs etc. Prime example for this would be the Silverstone ML11.

If USB4 is the goal - whyever that would be - Gigabyte got you covered, there is the X870M Aorus Elite, albeit only 2 m2 slots.

I've just ordered myself the MSI B850M Mortar, which is a good intermediate board, with 3 m2 slots, optional "old" wifi antenna choice, and 2x PCIe slots, one being a regular x4, not just x1. No USB4, but the need for it is mostly negated by the rest of features.

 

[MarcParis]

How would a Jiushark JF13K Diamond fit?

I looked at it. Most probably it is compatible but the assembly mechanism is just...terrible..

Smallest mATX I know is 5L. True, it only works as APU with either external brick or AC/DC adapter stuff, but it's totally doable. More approachable options sit between 7 and 10L, allowing for LP GPUs etc. Prime example for this would be the Silverstone ML11.

If USB4 is the goal - whyever that would be - Gigabyte got you covered, there is the X870M Aorus Elite, albeit only 2 m2 slots.

I've just ordered myself the MSI B850M Mortar, which is a good intermediate board, with 3 m2 slots, optional "old" wifi antenna choice, and 2x PCIe slots, one being a regular x4, not just x1. No USB4, but the need for it is mostly negated by the rest of features.

Ahah smallest case size can be crazy. I remembered a 3L for an ATX MB...but that's all..
Nice board this B850M Mortar, 5G network, 2*gen5x4 m.2 + 1*gen 4x2 m.2.
What type of usage would you dedicated it?

 

[hrh_ginsterbusch]

I looked at it. Most probably it is compatible but the assembly mechanism is just...terrible..

Ahah smallest case size can be crazy. I remembered a 3L for an ATX MB...but that's all..
Nice board this B850M Mortar, 5G network, 2*gen5x4 m.2 + 1*gen 4x2 m.2.
What type of usage would you dedicated it?

My main system was and always is a workstation, so its main tasks are gonna be CPU-intense work (primarly audio editing / processing, web development, graphic processing, graphic design).

I am happy to say I'm fully gonna use ALL of the m2 slots, and luckily, those are, at least on the spec sheet, not sharing any lanes with each other, esp. not with the GPU. But even if they were, my GPU is just Gen 4, so it should be all good.

cu, w0lf.

 

[MarcParis]

It should be all good!

 

[NickO]

Hello! I've been working on a similar build and this has been a great resource, very inspiring. I've basically got it finished now except for the gpu, which I plan to replace with a 5080 Super when they become available. The 3050 will be used as a dedicated PhysX card.

 

[MarcParis]

Hello! I've been working on a similar build and this has been a great resource, very inspiring. I've basically got it finished now except for the gpu, which I plan to replace with a 5080 Super when they become available. The 3050 will be used as a dedicated PhysX card.

Nice setup.
Your airflow has some possible optimizations..
The front fan seems useless and the C14S fan should be as exhaust, especially when you will get your RTX 5080 Super exhausting 400W of heat.

 

[NickO]

Nice setup.
Your airflow has some possible optimizations..
The front fan seems useless and the C14S fan should be as exhaust, especially when you will get your RTX 5080 Super exhausting 400W of heat.

Thanks! I originally had the C14S fans as exhaust but when I switched them to intake my temps dropped by 5-10 degrees. The 3050 (Palit KalmX) uses passive cooling so having the front fan does seem to make a difference while gaming. I'll have to reevaluate once I get the 5080 Super.

 

[MarcParis]

Thanks! I originally had the C14S fans as exhaust but when I switched them to intake my temps dropped by 5-10 degrees. The 3050 (Palit KalmX) uses passive cooling so having the front fan does seem to make a difference while gaming. I'll have to reevaluate once I get the 5080 Super.

Fully agreed on your assessment!

On top if your GPU is passive, you can try a fan bracket also, but I don't if you would have enough space as you have some other expansion cards..

 

[MarcParis]

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Sliger S620 : A wind of change ! (01st January 2026)

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Background

Despite my love for the Cerberus-X since 2017, I did not lose my interest in the Mini-ITX form factor. All my recent experiments, either with the BD790i, the FormD T1, the R7 9800X3D inside the U-ITX. In fact I've been an advocate of mini-ITX since 2012 but the Cerberus-X was such a disruptive proposal for an ATX motherboard back in 2017 that I embraced it for my main rig since…but I always kept secondary setups on Mini ITX.

In fact, my current goal is simple : to build a good enough (even better) setup with a mini ITX motherboard in order to replace my Cerberus-X as my main setup!


My Specifications

• Thermal : The best on all the components (CPU, GPU, SSD)
• Noise : Silent during idle, i.e. the RTX 5090 FE has to remain fanless on idle and the other fans at around 400 rpm. Quiet during heavy load.
• Storage : 2xm.2 on the recto of the motherboard, with heatsinks
• Expansion : 2xUSB4 ports for further expansions, ie fast storage and/or 10G network
• Vertical GPU & CPU cooler orientation to avoid any sag
• Size : SFF volume, below 20l, aiming for 15l at most.

Build #1

With all those specifications, I decided to pick-up the Asus X870i as my motherboard because it was fulfilling all my requirements for a good price now (~350€ vs more than 500€ at its launch).

I hesitated also with the Asus B850i (lack of USB4 and m.2 at the verso) or the MSI X870i (compliant but still way too expensive at around 550€ currently).

The Asus X870i is a beautiful motherboard, pretty heavy for its size. To my surprise, please note that the handling manual is absolutely terrible, especially on the m.2 setup, either on their location (between slot 1 gen 5, down and slot 2 gen 4, up)...of course no explanations how to remove the heatsink / bridge.

After some trials/mistakes, the job is done. Note the small bend of the upper m.2. I tried to correct it (2 times already), but in vain. I’m not too concerned, as the SSD is working just fine and is taking its straight shape as soon as the heatsink is removed.

At last, the Asus X870i has 2 small fans (40x15 up to 10000rpm), one for the VRM, one for the Chipset. They cannot be controlled in the bios, but they can be monitored/controlled through HWInfo64 & Fan Control softwares. I tried to force them to 0 rpm…but I suffered instabilities with this build #1 due to that. Thus I let the standard fan profile but I’m monitoring them. Overall they are not audible versus the other fans.

Finally the only bug I’m facing with the X870i is its behaviour with the USB4 SSD enclosure I got (Ugreen D700, passive USB4). I’m reaching 3Go/s in read mode…but only 250Mo/s in write mode. I updated the firmware of the asmedia/USB of the X870i motherboard, but it is still buggy. I’ll try another SSD enclosure and let you know. One positive point is that Samsung Magician is capable of recognizing & handling the 990Pro inside the external USB4 case while connected to USB4 (not working if connected to standard USB 2/3 ports). I was even able to flash its firmware. If I connect the USB4 enclosure to a 10gbps USB port, its write speed reaches 800mo/s…so weird.


For the case, I selected the Sliger S620 on which I implemented a simple but noticeable change : the power AC extension cable.
It is a default I noticed on all the Sliger case, either the Cerberus-X, SM550, CL530 or the S520…the power extension cable as an angle that is projecting the cable at the opposite of the Corsair SFX PSU, making some PSU orientation impossible to fit. I suppose Kimera / Sliger selected this orientation back when Silverstone was the leader of the SFX PSU (2016)...now even Silverstone has aligned its PSU plug orientation to Corsair..
Thus I used the power AC extension cable from SFFtime, either the N-ATX or the U-ITX (same angle, same length) (Thanks @riba2233)


Here the side view of the build #1

As a direct comparison, here is the standard orientation on the SM550 with a Corsair SF450

But why using this specific Power AC extension angle? Simple, with that angle I’m able to put my SF1000 with its intake fan towards the innards of the case, instead of the outside…allowing me to use the Sliger S620 in the desktop (horizontal) orientation, like my beloved Cerberus-X. In this stand, both the GPU & the CPU cooler have no sag.

As other interesting points, I’ve used 2 fans (ie Fractal Design HP-12, for their grommet corner and easy removal) as intake for the RTX 5090 and 2 fans (Noctua NFA12x15 Chromax) as exhaust on the side bracket.
The CPU cooler is the ID-Cooling IS-67XT with a Noctua NFA12x25 Chromax.

Here is the full component list :

• Case : Sliger S620, desktop-horizontal orientation
• Motherboard : Asus X870i
• CPU : AMD R7 9800X3D (CO -14)
• RAM : Corsair Vengeance 2x24Go DDR5 7600 MTS CL36 (DOCP I profile)
• CPU Cooler : ID Cooling IS-67XT + Noctua NFA12-25 Chromax
• RTX 5090 FE : Undervolted
  Core Curve : 825-910 : 2700 MHz
  GDDR7 +3000
  Power limit : 100%
• SSD #1 : Samsung 9100 Pro 2To (Slot 1 gen5)
• SSD #2 : WD SN850X 2To (Slot 2 gen4)
• SSD #3 : Samsung 990 Pro 4To Through USB4 port
• Bottom Fans : 2xFractal Design HP-12 (intake ~1000rpm)
• Side Fans : 2xNoctua NFA12x15 Chromax (Exhaust ~1100rpm)
• Custom fan curve : Yes ("Fan control" Software)

Build #1 Performance

For the CPU, i.e. the R7 9800X3D (curve optimizer -14), the IS-67XT is not strong enough to unleash its full potential. I ran a Cinebench 2024 (multicore score of 1282). Please note I have also updated the R7 9800 X3D firmware to AGESA ComboAM5 PI 1.2.7.0 and it is difficult to compare with my previous scores.

This result is not surprising and I even found the same result as my previous experiment within the N-ATX. The IS-67XT is capable of sustaining a power of 130W maximum.

For the RTX 5090 FE, well, well, I was very surprised as this setup is simply beating my Cerberus-X…by 2°C! (72°C vs 74°C, while at stock, 575W tdp) I was not expecting better cooling on the GPU, especially as I just tested the S620 with the BD790i last week. Le secret? The addition of the 2xHP12 fans just in front of the RTX 5090 FE fans. Those fans are acting, exactly like the ones of the fan bracket in my Cerberus-X but with even better positioning.

You can find the links to my other videos of this torture test in the description of the video.


However the CPU (83°C) & SSD (56-57°C) temperatures are just OK, could be better.



Regarding the gaming performance, it is top notched! It is powerful, cool enough & quiet.



At last, during idle/desktop mode, the RTX 5090 FE remains fanless, thanks to the dual HP-12 fans, just in front of it. Here is a screenshot of 2 hours of idle time…my RTX 5090 FE fans never spinned…

Following the success of this build #1, I will pursue my investigations!

 

[MarcParis]

Well, well, The King is dead, long live the King!

My Cerberus-X is beaten by my S620 as I paired it with the Noctua D15S!

More details on my dedicated thread :
https://smallformfactor.net/forum/threads/sliger-s620-itx-master-piece.16505/post-295274

 

[MarcParis]

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Cerberus-X March 2026 : The return of the Phoenix (29th March 2024)
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As you may know, I switched (tried) a mini ITX setup with my R7 9800 X3D inside the S620 in order to test on it the “allmighty” NH-D15S.

Overall this was a positive experience with up & down.

• Positive Points :
  • Excellent Thermals
  • Good Noise profil
• Negative Points :
  • The build is too crammed for my taste (removing the CPU heatsink remains the starting point for pretty every maintenance operations)
  • Since I got the R7 9800X3D I was displeased by its behaviour on desktop mode : many power spikes to handle even standard operations (ie downloading a game on Steam) resulting in very noticeable fan bursts. Definitely this chiplet design is hard to cool, even for the NH-D15.
  • Bad experience with the Wifi/Bluetooth module, Mediatek MT7927, even on Windows. On Linux, no official driver.
  • On Linux, shutting down the pc is not shutting down the USB (On Windows 11, it is working just fine)
  • Asus Armory crate : my god, this piece of software is just crap!
  • Asus X870i : Some compatibility issues whereas my 9100 pro, while connected to the m.2 gen5 slot, is not loading in Bios, leaving the system to be stuck in the Bios. Strangely it did not happen when the SSD is positioned in the m.2 gen 4 slot. A new assembly allowed to reduce the issue occurrence however.

To be honest, never a CPU like the R7 9800X3D made me change my motherboard so many times…already 4 ! (MSI X870 Tomahawk, Asus B650I, Asus B850-E, Asus X870I)

The worst point is that I’m not satisfied by it! In a pure paradox, I prefer my 12600K behaviour, and by far, even if it was clearly less performant. I even thought to upgrade to a 14600K or 14700K, but I prefer to wait for other alternatives.

Two factors influence my decision to get rid, for now, of my Sliger S620 but also from my R7 9800 X3D :

• My will to get rid of Windows 11 (and basically Microsoft products)
• A very potent Intel 270K release (Back to Nov 2024, I wanted to get the 265K, but it was really bad)

Thus I decided to move back to the Cerberus-X and the ATX motherboard form factor, giving a try to this shiny “new” Ultra 7 270K…and also to CachyOS.

More to come !

 

[rfarmer]

I'm curious to hear your thoughts on the 270k, I have one coming on Tuesday to upgrade my 265k. I wasn't sure about upgrading but Newegg offered my $230 for trade in which is only $70 less than I paid for it.

 

[MarcParis]

I'm curious to hear your thoughts on the 270k, I have one coming on Tuesday to upgrade my 265k. I wasn't sure about upgrading but Newegg offered my $230 for trade in which is only $70 less than I paid for it.

So far so good, really. I was already convinved that the Z890/B860 platform was better than AM5, limited by the i/o of Zen 4. Sadly for AMD, Intel locked all their wifi 7 module to Intel platform.

Now with the 270K, the LGA 1851 is complete, even if it the last iteration. That is announcing great stuff for Nova Lake, but I'm already scared by this new platform.. especially on the price..

 

[hrh_ginsterbusch]

So far so good, really. I was already convinved that the Z890/B860 platform was better than AM5, limited by the i/o of Zen 4. Sadly for AMD, Intel locked all their wifi 7 module to Intel platform.

Now with the 270K, the LGA 1851 is complete, even if it the last iteration. That is announcing great stuff for Nova Lake, but I'm already scared this new platform..

Yeah, 270K _IS VERY_ tempting, but I just got me all set up for B850, and my 7950X is still pretty solid, so I gonna stay for a while. And if, out of some reason, something REALLY needs more oomph, I just gonna upgrade to 9950X3D, which looks oh so solid in performance

cu, w0lf

 

[MarcParis]

Yeah, 270K _IS VERY_ tempting, but I just got me all set up for B850, and my 7950X is still pretty solid, so I gonna stay for a while. And if, out of some reason, something REALLY needs more oomph, I just gonna upgrade to 9950X3D, which looks oh so solid in performance

cu, w0lf

For sure I liked a lot my R9 7945HX, basically the mobile version of the 7950X. For sure the upgrade path is obvious with 9950X3D, now but tomorrow with 9950X3D2 and Zen 6 version (24/48 cores/threads)..
On Linux, AMD CPUs have very strong performance.
Nova Lake vs Zen6 should be quite an interesting battle!

 

[MarcParis]

Before moving on my 270 build, have you noticed that Sliger released its S640, the spîritual successor to the Cerberus-X?
Sliger S640

In terms of dimensions : S640 vs Cerberus-X
External : 31L 439.42mm x 190.50mm x 370.84mm [DxWxH] vs 20.87L 330.20mm x 177.80mm x 355.60mm [DxWxH]
Internal : 28.6L vs 19.64L

Compared to the 20.87L of the Cerberus-X, this is a massive increase, ie +48%

Motherboard : up to E-ATX (including Micro-ATX)
CPU Cooler Max height : 160mm, compatibble with 360 AIO (top or side), dual side bracket
GPU Card Max Height / depth : 160mm, 402mm
Price : 349$

I wonder how the rear fan is fixed...maybe there is possibility to have a rear fan.. (It is not listed on the website...only the top 3 fans are)

I'll wait for the first setups examples before considering it. At this size, it is most probably too big for me.

 

[MarcParis]

I just update the volume comparison of the Cerberus-X vs the S640. For outer dimensions, the gap is in fact of +48% vs the Cerberus-X, really massive.

 

[rfarmer]

I got my 270K yesterday and haven't done much testing but temps in Borderlands 4 are 55-62C which is decent and about the same as my 265K. Cinebench R23 temps went from 80-88C and considering the power increase isn't too surprising. Amazing thing is the score. 42,319 up from 35,657 on the 265K, you need a R9 9950X to hit 42k with Ryzen. Using a 240mm AIO for cooling btw.