HL15-X11SPH-nCTPF MB, dual AOC-SLG3-2M2 riser cards

[DigitalGarden]

That’s actually the reverse of what I expected you to say you had an issue with. Slot 5 shares bandwidth with Slot 6, so there is an issue bifurcating Slot 5 as x4x4 when slot 6 is populated. See;

Inserting x16 PCIe card disables second slot

After hours upon hours of testing every combination, it seems that once the 16x is split between slot 5 and 6 (to x8x8) it cannot be split again to x4x4. I also wanted to confirm that auto splitting works fine when using an x8 and x16 card however not when using an AOC-SLG3-2M2 in slot5 while slot6 is populated. This card works great in slot 3. https://www.supermicro.com/en/products/accessories/addon/AOC-SLG3-2M2.php

For general guidance about where to find the bifurcation settings, see;

Any tips on getting the AOC-SHG3-4M2P to work?

No problem. I glad you have the card working. Have a good Thursday. As a supplement reference, I found some good detail in this PDF from “Server the Home” forum site. There was a link to pdf called “Setting up bifurcation.pdf”. As the document was 1 page, I screenshot the document as a PNG. While this talked about Dual M.2 Carrier Card, the logic is valid with 4 slot Carrier Card. [Screenshot 2023-12-07 at 12.26.04 PM]

Depending on what else is in your build, a simpler solution might be a 4x NVMe card in Slot 6 if you need 4 NVME.

There are other general posts here on this topic if you search on something like ‘bifurcation’ and read the ones specific to the X11SPH/HL15 V1.