Question Two PCIe cards on Single Slot Motherboards

[bodacious]

To shrink size of the overall system I'm looking into using a small motherboard (mini-ITX). Those motherboards only come with one PCIe slot, however I want to install a two PCIe cards (a graphics card and a comm card). I don't need the speed so both cards can run in x8 mode.

I'm looking for a PCIe splitter card that can split the x16 channel from the motherboard into two x8 slots. I tried a Supermicro GPU Riser Card (RSC-G2F-A66-X1) but was unsuccessful with that.

Are there any riser cards and/or combinations of riser cards + motherboards that would work with this setup?

 

[tennis2]

So you end up with 2 PCIe cards. Assume the GPU is 2 slot, and the Comm card is 1. That's 3 slots. What mITX case are you going to mount them in? Most* itx cases only have 2 expansion slots. If you use an mITX case with 3 slots, mATX is 4, so that would only add 1 slot to the height and an mATX board wouldnt require any special work-arounds for connecting more than 1 expansion card.

https://pcpartpicker.com/products/case/#t=9,12,10&sort=price&page=1&E=3,11

 

[bodacious]

This is mainly an exercise on how small you can go... mATX is pushing volume.
I was planning a case, similar to the JONSBO V11 case - see link below. This case (and a handful of similar cases) has 3 hardware slots that would fit a 2 slot GPU + the other card I need. Granted there might be some flexible PCI cabling required and the expander card needs to fit in the motherboard volume, but it's close.

(https://www.jonsbo.com/en/products/V11Black.html)

 

[tennis2]

Ok,
I'm not condoning this particular product, but:
https://ameridroid.com/products/m-2..._content=sag_organic&utm_campaign=sag_organic

Linus Tech Tips have done a few projects where they use an M.2 (which is PCIe) to connect an external GPU off a laptop or whatever. In this case, I'd obviously recommend connecting your GPU to the onboard PCIex16 slot and the capture card to this...thing.

This should start you down the rabbit hole at least.

https://www.walmart.com/ip/PCIe-x4-...mwuFqe3frcrOhrzsjZcY52eLbqI8UOEYaArS4EALw_wcB

https://www.aliexpress.us/item/3256...Product&gatewayAdapt=glo2usa&_randl_shipto=US