@Necere
You are right it is for a PSU mount and this will offer a epyc unique use-case.
And its made for LTT because he is one of the few out there that can give it a try.
I have not read all 57 pages of this thread, but I am liking the chassis...
( ...I did read all of the updates linked on the first page, and then I read EVERYTHING after the Update #12 - Thermal Testing... )
@dondan
Questions about actual mDTX compatability...
The only mDTX board I know of right now is the ASUS X570 / AM4 Crosshair VIII Impact mDTX mobo...
It is a great mobo, but there is the SO-DIMM.2 riser board on it, for a pair of 2280 M.2 SSDs, this board sticks up a fair bit, positioned right above the backplate of the GPU (in Classic Mode)...
Is this going to be an obstruction / interference issue with an AIO (240 or 280) mounted on the side bracket...?
Same question for Sandwich Mode, is the vertically mounted GPU going to cause an obstruction / interference...?
@dondan
Question towards thermals...
From the provided chart, it seems Classic Mode, with a deshrouded / defanned GPU in exhaust & a 240 or 280 AIO in exhaust, is the configuration that showed the best temps...?
( ...negative pressure with air intake via bottom venting & rear panel venting...? )
When the chassis is inverted, is there room for a pair of slim Noctua NF-A12x15 PWM fans on the bottom to assist intake...?
@dondan
In regards to the LinusHole...
You HAVE to get Linus to enter this chassis (with Epyc Fat ITX mobo & the highest-of-ends GPU) in the PPL (Performance Per Liter) thread
(most current is Number Four, found here)...!
An Epyc CPU & ultra high-end GPU in 12.77L would crush the competition...!
( ...until Fabio rises to the challenge with an Epyc build & dual GPUs...? )
If you want to see how the A4-SFX is representing for you in the previous three rounds...!
Round One - not collated in leader boards, I did not survey / tabulate the thread for results
Round Two - no entries with the A4-SFX...?
Round Three - Four entries with the A4-SFX
Over on the PPL thread(s) it has been established that the PCIe brackets tabs that stick out the back do NOT need to be included in the bounding box dimensions of the chassis...
( ...this same allowance to PPL bounding box measurements is what allows the Cooler Master NP200 to actually BE a SFF chassis at about 19.6L...! )
BUT the feet DO need to be included if they are there to lift the chassis & allow airflow in/out of bottom venting/perforations...!
@dondan
So the PPL bounding box dimensions for the C4-SFX would be (H x W x D) 257 x 151 x 329mm, 12.77L...!
Getting him to run those tests & post to the thread in his eventual video would be extra cool exposure for the C4-SFX chassis, SFF.N & the PPL competition(s)...!!!
I have the C8I mobo with a 3900X, 32GB 3600/16 RAM (Samsung B-die), & two 1TB NVMe M.2 PCIe Gen4 SSDs...
I will be getting a 6800 XT, probably the Sapphire Nitro+ once the prices come back to reality... This card would be perfect for deshrouding / defanning & using in the Classic Mode inverted (now standard?) C4-SFX chassis...!
Power is a SF750 with five sets of cables to choose from...! ;^p
Thanks
@dondan ...!!!
EDIT TO ADD:
The Sapphire Nitro+ 6800 XT has a measurement of 134.3mm, but deshrouding / defanning it should take some off of that measurement, as well as removing the RGB light bar along the top edge of the PCB/backplate...?
The two 8-pin power connectors on the GPU are well recessed on the PCB though...!