X399 Taichi / PCIE problems

Just wanted to report that the 3.50 version of the BIOS has improved the PCIe issues I was having the Fresco USB cards and HBAs.

The Dell HBA seemed to work, but I noticed some NVME checksum errors I have never seen, so I swapped it with an LSI HBA and the checksum errors disappeared. I plan to make a test pool and copy data on/off of it for a few days to see if there are any issues.

For the Fresco USB card... If I put it in the 1x slot it works fine, but gets grouped with all the motherboard devices and I cannot pass it through under linux to a windows vm. Again, otherwise it works just fine in Linux or Windows. If I put it in a 16x or 8x slot, it does get put in it's own group and I can pass the whole card to a Windows VM.

Previously, both these cards, the Fresco USB 3 card and the HBA would cause lockups if they were installed.

Glad to see progress here.

if 3.50 does not work ping me and i'll drop the bios 3.33e for you to test.

The asrock support helped me solve the issue; they provided a beta bios 3.33e (which does not seem to be available on the web).
My decklink x4 pcie gen2 is now recognized.
The pcie slots are still not working properly (i have a GPU + 1 pcie x4 + 3 pcie x1 cards, but i can't use all of them, only GPU + x4 + 2 x1).
But this is already a substantial progress.

Any update on that issue ?
I have exactly the same issues with a x4 gen 2 PCIe decklink card : the bios gets locked with Dr Debug error code 97 on all the x16 slots.
It works however on the x1 slot.
I've tried last bios 3.30 and last beta bios 3.33D .
This HEDT MB should have all PCIe slots functional. It's a pity it can't accept pro hardware.

Centraleurope, I think almost all boards will be like ASRock in that up to date documentation on the BIOS settings does not exist.  I have asked ASRock support and there was no help there either.  This forum is about as good a place for information as any.  Enjoy, John.