https://forum.asrock.com/ Copyright (c) 2006-2013 Web Wiz Forums - All Rights Reserved. Mon, 25 May 2026 23:21:59 +0000 Tue, 18 Mar 2025 04:40:32 +0000 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 12.04 360 https://forum.asrock.com/RSS_post_feed.asp?TID=101347 https://forum.asrock.com/forum_images/web_wiz_forums_black.png https://forum.asrock.com/ https://forum.asrock.com/forum_posts.asp?TID=101347&PID=185705&title=x470-taichi-pcie-bifurcation-problem#185705 Author: eccential
Subject: 101347
Posted: 18 Mar 2025 at 4:40am

Sounds like BIOS bug. You should contact AsRock tech support for that.
In the mean time, you can stay at 5.10 as NDRE28 suggested.
]]> Tue, 18 Mar 2025 04:40:32 +0000 https://forum.asrock.com/forum_posts.asp?TID=101347&PID=185705&title=x470-taichi-pcie-bifurcation-problem#185705 https://forum.asrock.com/forum_posts.asp?TID=101347&PID=185698&title=x470-taichi-pcie-bifurcation-problem#185698 Author: NDRE28
Subject: 101347
Posted: 18 Mar 2025 at 2:19am

Hi!

I'd downgrade the BIOS version to the one that worked well (v5.10).

Sometimes, new BIOS versions are worst, in some areas, than the old ones. ]]> Tue, 18 Mar 2025 02:19:51 +0000 https://forum.asrock.com/forum_posts.asp?TID=101347&PID=185698&title=x470-taichi-pcie-bifurcation-problem#185698 https://forum.asrock.com/forum_posts.asp?TID=101347&PID=185687&title=x470-taichi-pcie-bifurcation-problem#185687 Author: aswin
Subject: 101347
Posted: 17 Mar 2025 at 10:11pm

Hello,

I am experiencing an issue with the PCIe bifurcation (PCIe x16 switch) feature after updating the BIOS beyond version 5.10. My current configuration is as follows:

PCIe Slot 1: GPU installed.
PCIe Slot 3: Uses a PCIe-to-U.2 converter to support two NVMe U.2 SSDs.
PCIe Slots 2, 4, and 5: Each occupied by an SSD.
M.2_M1 Port: NVMe SSD installed.
With BIOS version 5.10 and earlier (including 4.xx), all SSDs are recognized correctly using PCIe bifurcation in an x8/x4/x4 configuration. However, in BIOS versions 8.xx and 10.xx:

When PCIe bifurcation (PCIe x16 switch) is enabled, the NVMe SSD in PCIe Slot 4 is not recognized.
When I disable PCIe bifurcation (by setting it to x16 mode), the NVMe SSD in PCIe Slot 4 is recognized, but the two U.2 SSDs in PCIe Slot 3 (via the PCIe-to-U.2 converter) are not recognized.
This issue does not occur in BIOS 5.10 and earlier.Any idea?

]]> Mon, 17 Mar 2025 22:11:05 +0000 https://forum.asrock.com/forum_posts.asp?TID=101347&PID=185687&title=x470-taichi-pcie-bifurcation-problem#185687