B450 Pro4 PCIe conflict
Printed From: ASRock.com
Category: Technical Support
Forum Name: AMD Motherboards
Forum Description: Question about ASRock AMD motherboards
URL: https://forum.asrock.com/forum_posts.asp?TID=113455
Printed Date: 16 Feb 2026 at 7:13pm
Software Version: Web Wiz Forums 12.04 - http://www.webwizforums.com
Topic: B450 Pro4 PCIe conflict
Posted By: gordenf
Subject: B450 Pro4 PCIe conflict
Date Posted: 14 Feb 2026 at 7:47pm
|
Hi, I have a problem with dual GPUs and nvme ssd in M2_2, it seems PCIE4 GPU conflicts with M2_2 nvme ssd. I had a pin-misdefined ssd(cant be recognized in M2_1), so I can only mount it into M2_2 with bios setting 'Force nvme for M2_2 Slot'. With one GPU mounted in PCIE2(3.0 x16), everything ran smoothly. Then I bought another GPU and mounted it into PCIE4(3.0 x4), found that Windows can't recognize the PCIE4 GPU. That was strange, as M2_2 has nothing related to PCIE4(which shares lanes with M2_1), as M2_2 shares lanes with sata3_3 and sata3_4. Then I tried turning off 'Force nvme for M2_2 Slot', not even removing ssd from M2_2, just rebooted(yes, this nvme ssd not showing in bios), booted another windows from ssd in sata3 slot, PCIE4 GPU showed in Taskmgr. Quite strange... so, any suggestion? CPU: R7 5700X MB: B450 Pro4, P10.43 beta(latest version) RAM: 32GB DDR4 3200 SSD: Kioxia EXCERIA PLUS G3 |
Replies:
Posted By: Xaltar
Date Posted: 16 Feb 2026 at 4:22pm
|
I would guess that the setting to force NVMe for M2_2 disables the PCIe4 slot. NVMe uses 4 lanes where SATA3_3/4 only utilize a single lane between them. By forcing NVMe on M2_2 the other lanes need to be taken from the PCIe slot. You can https://tw.asrock.com/events/tsd.asp" rel="nofollow - open a support ticket and ask ASRock for a more definitive answer but based on your description that is what's happening. ------------- 
|