Hello everybody,
I just thought I would share a nice fact about the Asus Z790 Hero and its last PCH connected PCIe slot. Fun fact you do not have to use the Asus add in card for bifurcation, I bought a dual U.2 to pcie x8 adapter and enabled x4 x4 in the bios to create a 905P raid 0 array for my windows install.
I am also trying to run an intel 25Gbits/s nic in the second x8 pcie slot, xxv710 da2 but I am struggling to get 25Gbits/s send speeds from my machine to the Truenas scale iperf3 server (running iperf3 with the reverse will get me 17Gbits/s or so rather than the 9 Gbits/s I’m seeing when sending from my desktop to the server)
Strangely, when using a regular old samba share on my Truenas I can get the 25gbps both ways…
Just thought I would share about the bifurcation working with an amazon u.2 adapter… The Q1T1 performance doesn’t improve much from using Intel VMD Raid … but the latency stays low which is nice. If you have any ideas about getting full 25Gbits/s iperf3 results both ways please share.
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Hi,
I have an asus z790, but I haven’t been able to get bifurcation working. Could you share which dual U.2 to pcie x8 adapter you used and screenshots of your bios changes?
I’d really appreciate it. 
Howdy,
This is the card that I bought on Amazon for dual u.2
I’m using two Optane 905p’s.
You have to have the card in the bottom most pcie x16 slot (G4) and there is a setting in the bios that sets that slot to x4/x4 bifurcation. It is located at
Advanced >> onboard devices configuration >> pciex16(g4) configuration.
If you set that to dual m.2 ssd… both nvme devices should show up in the bios and you can make a raid array with vid if you want.
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How did u raid them? Is there a setting in the bios? Which software allows you to configure two optane drives as raid?
It’s called intel vmd in the bios. There is a level one video talking about it for the z690 boards if I am not mistaken.
Basically you enable the vmd thing for the cpu, and then reboot the bios… when you re enter bios there will be a vmd setup option and you can make your raid array.
I wonder if there is a way to do this on am5. What would happen if i slipped this card into a x670e hero? Would only one of the drives show up?
If I understand correctly… the raid support on amd is very bad. Don’t do it to yourself!
