PCIe x16 NVMe Extension Card Compatibility

[ShinobiRen]

TL;DR: You cannot run an HBA and Asus Hyper M.2 x16 Gen 4 card and utilize all 4 NVMe drives (at least from the testing I have done - if anyone has been able to get this to work please let me know!)

 

I plan on posting my entire build process for my "stable" server once it is finally complete and I have all the resources together but wanted to post this in the off chance anyone has the same or similar setup I am running and runs into this issue. 

 

I am running a Ryzen 3900x CPU with an Asus ROG Strix X570-E motherboard. These are leftovers from a gaming computer upgrade I did earlier this year to get on AM5 but it got me thinking - Asus makes this handy NVMe expansion card here: https://www.asus.com/us/motherboards-components/motherboards/accessories/hyper-m-2-x16-gen-4-card/

I happened to have 4 spare NVMe drives from doing upgrades for my kids PCs last year that I haven't recycled yet so why not give it a shot?

I bought the expansion card, got it slotted, configured the BIOs to pass off all four to HexOS (TrueNAS) and was able to create a nice 3 TB pool in RaidZ1: 

 

No problem there. I went to add in an HBA (9300-8i) and the NVMe card dropped two drives from it. Tried every BIOs setting in the world I could think of but no dice - if I wanted to run the HBA and the NVMe expansion card I could only have two NVMe drives. 

 

Hope this helps if someone else has this same issue!

Edited 4 hours ago by ShinobiRen
Put the TL;DR at the top where it belongs