Sketch of a <8L mITX cube with ATX PSU support.

[iFreilicht]

(Imagine the Top+Side cover to be perforated)

This is just a draft, but I wanted to get the idea out, it was in my head for a week or so

There are a lot of cube cases like the Jonsbo C2 that use the free space above the mainboard for the PSU, which of course has the inherent problem of blocking airflow for the CPU. This layout uses a flexible riser to let the mainboard an PSU swap positions while the GPU remains mostly unaffected. That way, all three major components get air from the outside directly.

In this draft, the volume is 7.36L, the PSU is of the ATX formfactor and the available space for CPU coolers is ~58.5mm, but it would also be possible to go down to SFX and increase the CPU cooler height to fit something like the Cryorig C1 in there.

The idea behind using ATX was to increase the pool of components the user could choose from and/or reuse, and to avoid problems people are having with the SFX PSUs from Silverstone. I wanted to have the entry bar to SFF as low as possible.

The clearance for PCIe connectors with the higher mITX PSUs that ASUS and Gigabyte are offering is minimal, but they would fit.

As you can see, there is still space for two 2.5" SSDs (7mm) or one HDD (15mm).

The space below the GPU is for cabling and the flexible riser.

I know we're having a lot of case ideas in the last few weeks, don't judge me

 

[MrGuvernment]

mm, this looks similar to all existing cases of around this size....

 

[iFreilicht]

mm, this looks similar to all existing cases of around this size....

Show me one that has this layout.

 

[Kasul]

I think you should turn it upside down so the GPU is sucking the air in from below and the hot air exhausts upward and and also the same for exhausting the PSU out.

 

[Screes]

So basically an SG05 with the PSU under the motherboard instead of over?

You know you can fit a full size ATX PSU in an SG05 right?

 

[Kasul]

I don't know much about other case(s), I'm just saying your design telling me all the hot air will go to GPU because it's at the top if it stand on that orientation.

 

[iFreilicht]

I think you should turn it upside down so the GPU is sucking the air in from below and the hot air exhausts upward and and also the same for exhausting the PSU out.

I don't know much about other case(s), I'm just saying your design telling me all the hot air will go to GPU because it's at the top if it stand on that orientation.

Reasonable thought. I don't think it would really be a problem as this case is employing a positive pressure design, so the air that rises to the GPU should be pushed out the side again by the CPU cooler, or at least that's the idea. If my theory is correct, then the GPU would actually get cooled a little bit on the back. If yours is correct, then the GPU would get heated up from the back.
I think it will be hard to determine who's right without actually building that setup or taking a similar case and testing with that.
Do you think it would help if there was a fan in the front and exhausts at the back?

So basically an SG05 with the PSU under the motherboard instead of over?

You know you can fit a full size ATX PSU in an SG05 right?

Yes, and turned over by 90° and shorter. As I said, there are many cases where the PSU is above the CPU fan like that, and if you use a full ATX PSU in the SG05, higher profile CPU fans are going to have a hard time pulling in air, it's pretty much fighting with the PSU fan for it.
Of course, with the design of the SG05, the CPU will still be cooled decently as the front fan is pulling air through the whole case or you can use an AIO cooler.

 

[backfeed]

Interesting idea, I like it.

One problem would be the very limited space for the usually rather massive bundle of psu cables, though. Even modular cables would have trouble squeezing in, I guess?

 

[iFreilicht]

Interesting idea, I like it.

One problem would be the very limited space for the usually rather massive bundle of psu cables, though. Even modular cables would have trouble squeezing in, I guess?

Quite probably, but it depends on the PSU, of course. From what I could tell, modular connectors need at least 20mm for the cables to bend somewhat freely, 15mm is the absolute minimum. Because the connectors on the PSU may extrude a bit, you can get into trouble with PSUs longer than 150mm. (The PSU in the pictures is 140mm long.

Especially PSUs with a higher power rating and thus more cables that are not at least partially modular could be a problem, the one in my old PC has such a shitload of cables attached to it, the whole bundle would need at least 40mm to bend.

But you have to remember that ATX PSUs are 86mm tall, so if you can get the cables around the corner, it should be possible to tuck them in the space between front wall and PSU in most cases.

You know you can fit a full size ATX PSU in an SG05 right?

After looking into it, that statement is a bit misleading. The SG05 doesn't have mounts for a full size ATX PSU, but there is enough space so you can do it with modding.
The SG13, the SG05s successor, though, has a larger mount for ATX PSUs. Maybe you even meant the SG13?