Tiny Motherboards

[Sonefiler]

Hey everyone!

 

I'm in the planning stages of an incredibly ambitious build, and I need the PC to be as small as possible while still having all the features that I need for this PC to function. 

 

Right now, I'm looking at this ASRock motherboard. It's a mini-STX board (140mm x 147mm), and you may note that there is no PCI-E port on it. 

However, this motherboard has some CRUCIAL features:

 

a.) takes a DC input (which means I don't need any SFF power supply or anything, or even an internal power supply at all)

b.) has TWO PCI-E 4x M.2 ports that go directly to the CPU (not to a separate PCIE processor thing that a lot of motherboards have). 

 

My plan is to combine these two M.2 ports into one PCI-E 8x port with a riser cable, and (hopefully) be able to connect a high power graphics card. This Puget Systems article indicates that 8x vs 16x should have zero impact on the performance of the system. However, I'm not sure if this is the best option. There are other options available; I could go with an Intel NUC, but as far as I can tell, there is no NUC board that has 8x of expansion bandwidth available. I could also try to loot something from a pre-existing computer, but the time and effort it takes to research all the different OEM motherboards would take ages, and I already have enough on my plate as it is. I've also heard about MXM graphics cards, but I don't really know what they are or how they work, so information on that would be really useful.

 

 

Here's where I need the help. I want to find more options for my motherboard. All it needs is the ability to have at least PCIE 8x total, directly to the CPU. (I can figure out the power stuff if necessary, if it's that small then it probably won't be too big of a deal.) Please let me know if you have any information that may help me! Thank you so much!

[Fasauceome]

Doesn't a big eGPU defeat the purpose of the mini form factor? Might as well get ITX at that point. Asrock is making an AM4 STX board, why not wait for one of the rumored Ryzen CPUs that will have updated integrated graphics and run with that?

https://www.tomshardware.com/news/asrock-am4-motherboard-ryzen-amd,38391.html

[Sonefiler]

1 minute ago, fasauceome said:

Doesn't a big eGPU defeat the purpose of the mini form factor? Might as well get ITX at that point. Asrock is making an AM4 STX board, why not wait for one of the rumored Ryzen CPUs that will have updated integrated graphics and run with that?

https://www.tomshardware.com/news/asrock-am4-motherboard-ryzen-amd,38391.html

I'm trying to fit a computer into the size of a (large) model train. No one part can be too big or else it won't fit into the size of a train car. 

[Fasauceome]

1 minute ago, Sonefiler said:

I'm trying to fit a computer into the size of a (large) model train. No one part can be too big or else it won't fit into the size of a train car. 

Then I have no clue where the GPU would fit into that equation, likely being the biggest part. Presumably you could do away with it entirely, what did you have in mind in terms of horsepower?

[Sonefiler]

Just now, fasauceome said:

Then I have no clue where the GPU would fit into that equation, likely being the biggest part. Presumably you could do away with it entirely, what did you have in mind in terms of horsepower?

Well, my idea is that I would be able to separate the GPU into another traincar, and just have the cars be interconnected via a riser cable or something along those lines. and I don't think the GPU will necessarily be the biggest part. It will obviously be thicker than the motherboard, but I don't think that will be an issue. There are plenty of small form-factor graphics cards in existence, and even some of the bigger ones won't be too big of a deal (I think). 

In terms of horsepower: I just want to be able to run CSGO at 200FPS, something along those lines. Ideally I will fit as much horsepower as is possible into the thing, but I don't know yet what's feasible. 

[badreg]

Where do you see that the E key M.2 slot is x4, and that both M.2 slots are wired directly to the CPU instead of going through the chipset? Additionally, you only get 25W out of a single M.2 slot, so you would be limited to 50W if you manage to bridge the two slots.

[Sonefiler]

9 hours ago, badreg said:

Where do you see that the E key M.2 slot is x4, and that both M.2 slots are wired directly to the CPU instead of going through the chipset? Additionally, you only get 25W out of a single M.2 slot, so you would be limited to 50W if you manage to bridge the two slots.

Upon closer inspection, I'm actually not sure where I got that first idea. As far as I can tell, only one of them is wired directly to the CPU. I don't know what kind of negative performance impact that will have. I do know that both are x4, since it does say that on quite a few of the pages that I've looked at about this motherboard. I guess that's another thing that I will have to look into. 

 

50W should probably be fine for my use case. I will need to be careful to choose a card that has a little extra leeway with its power connectors, though, that is true. 

[Sonefiler]

Did some research. Turns out someone's done a tiny PC with this motherboard before, and has done the same thing with the x4 risers that I was planning on doing: https://smallformfactor.net/forum/threads/stx160-0-the-most-powerful-atx-unit-in-the-world.934/

[ch3w2oy]

24 minutes ago, Sonefiler said:

Did some research. Turns out someone's done a tiny PC with this motherboard before, and has done the same thing with the x4 risers that I was planning on doing: https://smallformfactor.net/forum/threads/stx160-0-the-most-powerful-atx-unit-in-the-world.934/

That's pretty cool.

 

Final build:

https://smallformfactor.net/forum/threads/stx160-0-the-most-powerful-atx-unit-in-the-world.934/page-16#post-36886

[Sonefiler]

Looking into it more, I guess that guy that I linked just fucked up? It doesn't seem like that second M.2 slot is x4. Was he just running his graphics on x4 this entire time? That's a massive bummer for me. It would explain why he doesn't have any benchmark numbers posted...