Nvme storage question on Taichi x870e mobo

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   I am building a pc using Taichi x870e motherboard and AMD 9950X3D, changing from an intel cpu and Asus ROG Maximus Hero. The Asus Mobo comes with a pcie expansion card that can hold a maximum of 2 Nvme devices. It is not independently powered drawing upon the pcie slot exclusively.
I?�m wondering if I can install this card in PCIe slot 2 ( with the gpu in slot 1) and be able to see both Nvme devices. I plan to populate the 4 Nvme motherboard slots as well. 
I need somebody who has knowledge of what the mobo and its chipsets can accommodate. It?�s a little bit above my tech grade and I?�d prefer to know ahead of time rather than determine by trial and error.
Help appreciated 
Ronharr

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Ronharr Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 15 hours 2 minutes ago Location: Canada Status: Offline Points: 35	Post Options Post Reply Quote Ronharr Report Post Thanks(0) Quote Reply Topic: Nvme storage question on Taichi x870e mobo Posted: 14 hours 40 minutes ago at 10:12am
	I am building a pc using Taichi x870e motherboard and AMD 9950X3D, changing from an intel cpu and Asus ROG Maximus Hero. The Asus Mobo comes with a pcie expansion card that can hold a maximum of 2 Nvme devices. It is not independently powered drawing upon the pcie slot exclusively. I?�m wondering if I can install this card in PCIe slot 2 ( with the gpu in slot 1) and be able to see both Nvme devices. I plan to populate the 4 Nvme motherboard slots as well. I need somebody who has knowledge of what the mobo and its chipsets can accommodate. It?�s a little bit above my tech grade and I?�d prefer to know ahead of time rather than determine by trial and error. Help appreciated Ronharr

eccential Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 10 Oct 2022 Location: Nevada Status: Offline Points: 5705	Post Options Post Reply Quote eccential Report Post Thanks(0) Quote Reply Posted: 6 hours 35 minutes ago at 6:17pm
	Look at the page 11 (as printed) / page 15 (pdf file) of the user manual. The two PCIe slots can run either as x16 / disabled or x8 / x8. Now, the question is, what does that PCIe -> m.2 x 2 card do? Based on ASUS page: "** When ROG Hyper M.2 card is installed on PCIEX16(G5)_1, PCIEX16(G5)_2 will run x8 only and if ROG Hyper M.2 card is installed on PCIEX16(G5)_2, PCIEX16(G5)_1 will run x8 only," I'm guessing that the card itself has no logic and depends solely on motherboard's ability to bifurcate. I'm assuming Taichi x870e can do x4/x4 bifurcation, at least on one of the PCIe slots. And if so, you should be able to use the m.2 splitter card on that slot, once BIOS setting for bifurcation is set properly. Now, I'm not sure if you can do this independently for the two PCIe slots. For example, if you want to use the top PCIe slot for GPU, then you'd want x8 + x4/x4. If you want to use the bottom PCIe slot for GPU instead, then you'd want x4/x4 + x8. No idea what configurations the motherboard supports. The other possibility is that the PCIe -> m.2 x 2 card has built-in PCIe bridge. If that's the case, it should just work, if with a slight bandwidth / latency handicap.

Ronharr Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 15 hours 2 minutes ago Location: Canada Status: Offline Points: 35	Post Options Post Reply Quote Ronharr Report Post Thanks(0) Quote Reply Posted: 4 hours 24 minutes ago at 8:28pm
	Thanks for your reply. The 2x2 card doesn?�t have any integrated circuitry that I saw when populating it. I assume that would be necessary to ?�bridge??the devices but this is a guess. I don?�t grasp the full drift of the bifurcation but you?�ve gone a long way to helping.

eccential Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 10 Oct 2022 Location: Nevada Status: Offline Points: 5705	Post Options Post Reply Quote eccential Report Post Thanks(0) Quote Reply Posted: 2 hours 35 minutes ago at 10:17pm
	According to this post, AMD/AM5 _can_ support all of these bifurcation settings: x8 / x8 x8 / x4 / x4 x4 /x4 / x4 / x4 https://www.reddit.com/r/Amd/comments/14bnqh3/guide_about_how_to_check_pcie_bifurcation_support/ The example given was using Gigabyte motherboard, so I have no idea what settings AsRock supports. I assume it supports at least the same level of bifurcation. I don't have a fancy AsRock AM5 board, so I can't test it for you, but chances are good that it will support x8 / x4 / x4 bifurcation.