https://forum.asrock.com/ Copyright (c) 2006-2013 Web Wiz Forums - All Rights Reserved. Fri, 15 May 2026 10:44:25 +0000 Tue, 06 May 2025 01:04:02 +0000 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 12.04 360 https://forum.asrock.com/RSS_post_feed.asp?TID=107781 https://forum.asrock.com/forum_images/web_wiz_forums_black.png https://forum.asrock.com/ https://forum.asrock.com/forum_posts.asp?TID=107781&PID=192533&title=question-regarding-pcie-bifurcation-on-b850m-slw#192533 Author: M440
Subject: 107781
Posted: 06 May 2025 at 1:04am

sr5ttyhrsyha wrote: I'd like to confirm if the B850M SLW (https://www.asrock.com/mb/AMD/B850M%20Steel%20Legend%20WiFi/index.us.asp#Overview) can have it's PCIe x16 slot bifurcated to x4x4x4x4 in order to allow bifurcation required type adapters (like https://www.amazon.com/GLOTRENDS-PU41-Bifurcation-Function-Motherboard/dp/B0D3XX7PSF) to work without a PCIe switch. I would be using a Ryzen 9700x CPU. Manual here: https://download.asrock.com/Manual/B850M%20Steel%20Legend%20WiFi.pdf Sadly, "bifurcation" and "x4x4x4x4" do not show up in a text search. However there is a section: >RAID ??Supports RAID 0, RAID 1 and RAID 10 for SATA storage devices > ??Supports RAID 0, RAID 1 and RAID 10 for M.2 NVMe storage devices* >* Requires additional M.2 NVMe expansion cards to support RAID 10 That indicates it may exist, but has just been poorly named. (Note to asrock marketing if you see this, mentioning "bifurcation" and "x4x4x4x4" is a good idea if those are supported. IF they are not supported, explicitly saying so is a good idea to remove doubt)

i tested mine b650m-hdv/m.2 - (8x/4x/4x) bifurcation of a main slot - A2000 GPU and 2x nvme, it works fine.

i think i can connect 6x nvme and gpu at pcie 8x to this board



Edited by M440 - 06 May 2025 at 1:18am]]> Tue, 06 May 2025 01:04:02 +0000 https://forum.asrock.com/forum_posts.asp?TID=107781&PID=192533&title=question-regarding-pcie-bifurcation-on-b850m-slw#192533 https://forum.asrock.com/forum_posts.asp?TID=107781&PID=192520&title=question-regarding-pcie-bifurcation-on-b850m-slw#192520 Author: NDRE28
Subject: 107781
Posted: 05 May 2025 at 3:43pm

Hi!

All I can say is that I'm using an X670E Taichi, which has two x16 PCIe slots, and which offers the following bifurcation options (and they do work):
1. x8x8 (top & bottom PCIe slots run in x8 mode).
2. x8x4x4 (bottom PCIe slot runs in x8 mode; top PCIe runs in x4x4 mode).
3. x4x4x4x4 (bottom PCIe runs in x4x4 mode; top PCIe runs in x4x4 mode).

NOTE:
Lanes can be upgraded or downgraded to: Gen5, Gen4, Gen3, Gen2, Gen1, but the lanes number remains the same!
With other words, you can't achieve more PCIe lanes by downgrading from Gen5 to Gen3.

I hope this helps...]]> Mon, 05 May 2025 15:43:53 +0000 https://forum.asrock.com/forum_posts.asp?TID=107781&PID=192520&title=question-regarding-pcie-bifurcation-on-b850m-slw#192520 https://forum.asrock.com/forum_posts.asp?TID=107781&PID=192499&title=question-regarding-pcie-bifurcation-on-b850m-slw#192499 Author: sr5ttyhrsyha
Subject: 107781
Posted: 05 May 2025 at 12:39pm

I'd like to confirm if the B850M SLW (https://www.asrock.com/mb/AMD/B850M%20Steel%20Legend%20WiFi/index.us.asp#Overview) can have it's PCIe x16 slot bifurcated to x4x4x4x4 in order to allow bifurcation required type adapters (like https://www.amazon.com/GLOTRENDS-PU41-Bifurcation-Function-Motherboard/dp/B0D3XX7PSF) to work without a PCIe switch. I would be using a Ryzen 9700x CPU.

Manual here: https://download.asrock.com/Manual/B850M%20Steel%20Legend%20WiFi.pdf

Sadly, "bifurcation" and "x4x4x4x4" do not show up in a text search.
However there is a section:
>RAID ??Supports RAID 0, RAID 1 and RAID 10 for SATA storage devices
> ??Supports RAID 0, RAID 1 and RAID 10 for M.2 NVMe storage devices*
>* Requires additional M.2 NVMe expansion cards to support RAID 10

That indicates it may exist, but has just been poorly named.

(Note to asrock marketing if you see this, mentioning "bifurcation" and "x4x4x4x4" is a good idea if those are supported. IF they are not supported, explicitly saying so is a good idea to remove doubt)]]> Mon, 05 May 2025 12:39:16 +0000 https://forum.asrock.com/forum_posts.asp?TID=107781&PID=192499&title=question-regarding-pcie-bifurcation-on-b850m-slw#192499