X570 Taichi NIC in 2nd PCIe not working
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=27064
Printed Date: 22 Dec 2024 at 2:09pm
Software Version: Web Wiz Forums 12.04 - http://www.webwizforums.com
Topic: X570 Taichi NIC in 2nd PCIe not working
Posted By: Paul88525
Subject: X570 Taichi NIC in 2nd PCIe not working
Date Posted: 08 Dec 2023 at 10:29pm
|
Hi, X570 Taichi with Ryzen 5600X and Nvidia RTX 4060 Ti. In addition, 2x Mellanox 2xSFP+ NIC (PCIe Gen3x8) and 1x Dual RJ45 NIC (PCIe Gen2x1). If I put the Graphics Card in the main PCIe slot and the Mellanox NICs in the 2nd (the one connected to the CPU) and last x16 one, the card in 2nd slot is not working. If I change the slots (NIC in 1st and last slot, Graphics Card in 2nd), everything works just fine. Is it possible that the board only activates PCIe slot 2 if there is a graphics card detected in it? Is there a possibility to force the board into bifurcation mode (8 lanes for both PCIe slots 1 and 2 ). I used the same board with differenct NICs (Myricom cards PCIe Gen2x8) which worked in slots 2 and 3 just fine, but with a different processor (5600G, which only supports PCIe Gen3). |
Replies:
Posted By: kerberos_20
Date Posted: 09 Dec 2023 at 12:53pm
|
it is possible that mainboard activates GEN4 for your GPU while your NIC doesnt supports GEN4 thus gets disabled in bios you can set gen3 x8/x8 for your two PCI-e slots connected to CPU which should make things work ------------- http://valid.x86.fr/diq4l4" rel="nofollow">  http://www.userbenchmark.com/UserRun/47132492" rel="nofollow - userbenchmark |
Posted By: Paul88525
Date Posted: 10 Dec 2023 at 5:27am
|
That could be possible, thanks for the input. Will try this Monday when I'm back at the office. But would that mean that the two slots connected to the CPU can't work at different PCIe GEN? This would be bad cause GEN3x8 for the graphics card would be too slow. I will check at what speed the card runs in 2nd slot. |
Posted By: kerberos_20
Date Posted: 11 Dec 2023 at 2:12pm
cpu provides 16 lanes on single bus, mainboard splits it through bifurcation not possible to have different gen on those x16 lanes, unless there will be some PLX switch ------------- http://valid.x86.fr/diq4l4" rel="nofollow"> http://www.userbenchmark.com/UserRun/47132492" rel="nofollow - userbenchmark |
Paul88525 wrote:Posted By: Paul88525
Date Posted: 12 Dec 2023 at 4:17am
|
I just tried it today, graphics card in 2nd slot runs on Gen4x8, while NIC in 1st slot runs on Gen3x8. When I swap the cards, graphics card still runs on Gen4x8, but NIC is not working at all (not recognized). I also did some tests with the same board, but different NIC (Myricom Gen2x8). This NIC runs in 2nd slot with same graphics card in 1st slot. The NIC runs at Gen2x8, while the graphics card runs at Gen3x8 with the 5600G and at Gen4x8 with the 5600X (which is expected). |
Posted By: eccential
Date Posted: 12 Dec 2023 at 10:56pm
|
I assume "2nd slot" is actually PCIe3, based on AsRock's naming from https://www.asrock.com/mb/AMD/X570%20Taichi/#Specification" rel="nofollow - https://www.asrock.com/mb/AMD/X570%20Taichi/#Specification PCIe1 is x16 (CPU) PCIe2 is x1 (X570) PCIe3 can be x8 (CPU) if bifurcation is enabled. PCIe4 is x1 (X570) PCIe5 is x4 (X570) shared with M2_3 M2_1 is x4 (CPU) M2_2 is x4 (X570) M2_3 is x4 (X570) shared with PCIe5 I believe the issue is the bifurcation auto-detection. You should go into BIOS can FORCE it to x8/x8 bifurcation. I have this same problem with my X470D4U, where it's SUPPOSED TO auto-detect, but it doesn't always work. |
Posted By: Paul88525
Date Posted: 13 Dec 2023 at 1:03am
|
Yes by 2nd slot I am referring to the 2nd x16 slot, so PCIe3. Can you tell me what setting I am supposed to change? I can only find PCIe x16 Switch, where the options are limited to Auto 4x4 2x4 1x8 1x8 2x4 The other options are for speed only (GEN1-GEN4). https://ibb.co/fHXsK40" rel="nofollow">  UEFI BIOS version is P5.50 (the latest). |
Posted By: eccential
Date Posted: 13 Dec 2023 at 1:39am
|
I don't own that motherboard. But the option choices are really unfortunate. 1x8 2x4. That means, PCIe1 will get 8-lanes (good for the GPU). But PCIe3 will get 4-lanes + 4 lanes. If the device you wanted to put into PCIe3 was x4 device, that would be fine, but since Mellanox card is x8, I don't know how it would react. Will it run using just 4-lanes? Will it get confused seeing two independent x4 lanes? I've no idea. I'm really shocked they don't offer 1x8 1x8 option! |
Posted By: Paul88525
Date Posted: 13 Dec 2023 at 2:10am
|
The cards run with X4 and x8 (2nd card is in slot PCIe5, which is only connected to the chipset with 4 lanes). But the PCIe switch does not make the card work in slot PCIe3 in any setting. Guess I'll have to stick to the current setup, graphics card in PCIe3, NICs in PCIe1 and PCIe5 and RJ45 NIC in PCIe2. |