Had some testing done at the weekend, here is my Summary:
On my first Board the 4i-SATA Port 3 was not working and at the same time the Fanout-Cable had the same broken Port...
That was nice... but after getting rid of these Problems, I tested with my two working Boards:
The 4i Port works with both SATA and PCI.
You can crossflash the Bios or use the EFI command, both ways are working fine (tested both)
The 4i Port is pretty bitchy about the inserted Cards.
I tried a dual 10G Card (x8) and a 1G Card (x1) and couldn't get them to work.
The 4x1G Card (x4) worked fine. I don't have more x4 Cards so I couldn't test others, it seems you have to use x4 cards to get them to work.
The 8i Port was more forgiving, I tried all the Cards which I used in the 4i Port and they all worked:
The Hardware I used:
Adapter:
https://www.amazon.de/dp/B0BZKCJVLG?ref=ppx_yo2ov_dt_b_product_details&th=1
Cable:
https://www.amazon.de/dp/B0CGXFJKJ5?psc=1&ref=ppx_yo2ov_dt_b_product_details
The Hardware for the 4i Port:
Adapter:
https://www.amazon.de/dp/B0BP254X7N?ref=ppx_yo2ov_dt_b_product_details&th=1
Cable:
https://www.amazon.de/dp/B0BLJPX9DF?ref=ppx_yo2ov_dt_b_product_details&th=1
I tried the following cable, that one didn't work:
https://www.amazon.de/dp/B0BZKF4RWM?psc=1&ref=ppx_yo2ov_dt_b_product_details
I ordered two of these 4i Cables, the first one was not working at all and the other one was 50% working.
What I mean with 50%:
You had to push the cable against the board for it to work. If I didn't press, the Card wasn't recognised.
Dunno' if that was the Adapter or the Cables fault.
What I learned after the weekend:
Most Problems seem to be the Cable+Adapter and not the Board itself.
The quality of these parts seems to be a gamble.
TL;DR: Cables and Adapters are a gamble, PCI works on the 4i and 8i Ports.
For the People running Debian/Proxmox:
I had to set the Port to PCI before installing the OS, if I installed with SATA and changed to PCI, Proxmox wouldn't recognise the Card.
For People with Problems on that Port:
The SATA-Fanout seems to be thicker than the PCI-Cable. The Pins in the 4i Connector seemed to be further back on my "broken" first Board.
Maybe this was a contact Problem.
--
@ilmari thanks for the answer
