BiosDude

OcuLink spec is governed by PCI-SIG and can be found here: pcisig.com You'll need to be a member to get access to the actual spec. Wiki entry can be found here: en.wikipedia.org Basically it stands for optical copper link. In enterprise storage servers, it is used to connect SATA, SAS, NVMe, & U2 backplanes to the baseboard using that same OcuLink cable.

I bought a replacement backplane in November 2018 for $25 + $6 shipping to WA after I managed to rip my top SATA connector off replacing my AsRock C2750D4i after it died. That replacement backplane has the 2 molex power connectors. So the modification to the backplane power connectors happened after that or I got old stock. The C2750D4i died under warranty so I got it RMA'd and only had to wait a month for the replacement. The replacement came with the latest BIOS and BMC. My build was using the SilverStone 450W ST45SF-G and worked great until it didn't. In May 2019, it stopped working in my NAS. There are threads here that mention the ST45SF-G has issues with the backplane. Sure enough, disconnect the backplane and the system boots. I replaced it with a SilverStone 500W SX500-G. The ST45SF-G was NOT on their approved list. The SX500-G was. While I was in there, I added another 16GB of ECC RAM for a total of 32GB; cleaned up the SATA cables to the backplane (I wish the backplane had SAS connectors instead of SATA to make cable management easier); and added some plastic cooling dams that attach to the side fans I bought on Tindie (they came with mounting screws.) With the infamous danioj skirt, I've seen the drive temps drop from the 40's to the 30's with the stock SilverStone fans. The AsRock C2750D4i has an insane number of fan connectors. 2 CPU fans (the board is passively cooled), 2 rear fans, and 2 front fans. All 4 pin connectors that will work with 3 pin fans too.