Probably a really stupid idea for a 12L SLI mATX case.

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PcZac

Limp Gawd
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Aug 30, 2013
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It's always really bothered me that computers, cases, and airflow typically don't work well together, there's a lot of 90 degree angles, perpendicular cooling, and working against hot air rising.

I had the idea to use PCI-Express extenders with graphics cards that have vertically aligned coolers (Gigabtye Windforce) remove the fans and to try to cool the whole system with only 2 fans and work with airflow and hot air rising. Here's my initial mock up, you could fit 4 3.5in drives on the opposite side of the motherboard, there's plenty of space back there because of the SFX PSU. If I was actually constructing the case, I would remove the shroud and fan from the PSU, It'll probably be nesicary to construct plastic air ducts to guide as much air as possible through the heat sinks. I'm still looking for the ideal CPU cooler to use for concepting. I'd like to keep it as quiet as possible, the top would have sound damping material that breathes to let the air out while minimizing noise and not holding heat next to your components.

Currently cable management and wiring hasn't be given too much though besides leave some space for it. The SFX PSU as a lot of room to be re-positioned.

Please tell me if this idea is stupid and why. Silent, powerful, and small PCs have always interested me.



9ww1MU1.png


Please imagine vertically aligned heatsink without fans on the GPUs and CPU. I'm planning on doing some photo-realistic renders once everything is planned and modeled.
 
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Hot air does rise (actually cooler, denser air displaces it) but its effects at the small scale of a computer case is greatly overblown.

That said, the basic concept seems feasible.

What's that block at the top for? I think it'd be a good idea to put two exhaust fans there if it isn't being used for anything.
 
I figured the top would let out the most noise, so I was planning on putting a few layers of sound damping foam, but it could be thinned out, or I could make it foam or space for slim fans depending on your wants. Also didn't want open vents dust could fall in when the computer is off.
 
Silverstone makes an entire series of cases with the internals rotated 90 degrees (the back of the motherboard is on the top of the case.) I don't know if that would interest you. Using PCI extenders isn't a terrible idea, but I think you're still going to need a fan on your CPU cooler/radiator with this setup because there just won't be enough airflow over it. That or a positively huge passive heatsink like the ThermalRight HR-22.

Raven series.
http://www.silverstonetek.com/raven/products/index.php?model=RV01&area=en
 
Assuming the motherboard doesn't have the chipset far down enough that airflow to it would be blocked by the 'front' GPU PCB, it could work. You'd need to use aftermarket heatsinks with a vertical fin orientation, and the CPU would be getting hot air from the GPUs. Reversing the airflow direction (thermal updraft is such a tiny effect in a PC case it can effectively be disregarded) would avoid that. With CPUs having a much lower TDP than a pair of GPUs, this may be preferable.
 
127mm x 310mm x 300mm = 11.8L

Those are about the smallest dimensions i could see with this layout. Might need to expand some of those a bit for fitting. But yea, 12L should be Do-Able. That would give you enough space on both sides (or top/bottom for vertical) for 25mm thick fans.

Rising heat is a lot less powerful than you think. It takes less than 10CFM worth of air movement to both counter and be more effective than convection. You don't really need to worry about it unless your going for a completely passive build. I would make the fans on both top and bottom (or both sides when horizontal) be intake, for a positive air pressure case, and plenty of cool air for both CPU and GPU regions.
 
I figured since the CPU heatsink could be larger in theory, that it wouldn't be a huge issue to have it after the gpu. Although if I had fans at the top and bottom you could easily reverse the case and test yourself. Maybe it would be quieter with 4 fans.
 
I love the idea, and I think it would work perfectly fine!

Actually, I did some testing with a mini-ITX board and a tower CPU cooler in this vertical setup.

The results were quite impressive: When the mobo was oriented as in your case idea, the CPU (i7-3770U) could be passively cooled to about 50°C under full load, while the temps just kept rising when the board was oriented horizontally, and you could easily feel the airflow above the cooler.

I think when you find the largest possible coolers, it would be possible to turn off all fans and make the system passive in idle, just letting the heat drive the air through the cooler fins.

Of course, that won't be enough during a gaming session, but it should be quite an effective cooling system nevertheless.

Additional idea: If you want to go as small as possible, you may want to try to use two FlexATX PSUs instead of one SFX. I have absolutely no idea how you would turn on the second one, but volume- and cooling-wise you could orient them in a way that would make the 40mm coolers obsolete.
Placing one on each side of the motherboard would give quite a nifty system, but it's probably overkill.


One last thing: Where is the SLI-bridge going?
 
There's too much of the MB being blocked by the front graphics card and it looks like the SLI bridges wouldn't work. AMD crossfire would work, I suppose, but just looks a bit too infeasable to do. Go with a dual GPU card and an ITX mobo.
 
I haven't spent too much time looking at bridges, I could move the back GPU up to make the bridge distance shorter.

There's no x99 itx mobo.
 
Ah, I've got an idea!

What if you turn the GPUs around by 180° so the SLI connectors face downwards? That would require a longer riser for the Card behind the motherboard, but I think it's the only way you'll get SLI working here.
 
rawrr said:
That's not the spirit man! We're here for innovation! :D
Click to expand...

Well here's a suggestion since you're asking for innovation: instead of having one GPU on each side of the motherboard, have them both parallel one on top of the other in front of the motherboard so the whole lot are vertical. Like a GPU layer over the motherboard. I'm not at home, so I can't do up a diagram in sketchup, so I'll attept to do it with text on my phone.

|G| [M]
|P| [O]
|U| [T]
|1| [H]
...... [E]
|G| [R]
|P|
|U| [R]
|2| [D]

Hopefully that makes sense.
 
I like that idea, but I think it would leave much to be desired for CPU cooling, plus there is no space for the PSU left.

Code: 
 |CPU| [M]
 |COO| [A]
 |LER| [I]
       [N]
       [B]
|G||G| [O]
|P||P| [A]
|U||U| [R]
|1||2| [D]

With this, the PSU could sit in front of the CPU cooler, SLI wouldn't be a problem, and the CPU cooler size could be pretty large. I think this would utilise the given space a lot better. Also, it would mean that both risers could be of equal length, which could be an advantage considering the SLI setup.
I know the delay for risers is very, very low, but SLI is quite vulnerable to that sort of stuff, at least from what I've heard.
 
With the extenders its not so much the length as it is interference.

3M makes a 250mm one but it's ~$100 due to the shielding and materials.
 
We still got LiHeat, they make shielded risers that seem to be of quite good quality. Not as top-tier as the 3M ones, but they also offer different insertion types, which can be quite helpful, too.
 
iFreilicht said:
Ah, I've got an idea!

What if you turn the GPUs around by 180° so the SLI connectors face downwards? That would require a longer riser for the Card behind the motherboard, but I think it's the only way you'll get SLI working here.
Click to expand...

I tried to wrap my head around the SLI bridge connector orientations but my brain blew up. This hardforum-hardware-custom-SFF-case-tetris-trend is producing some really original ideas though:D
 
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