X570 Taichi PCIe working at x8 instead of x16
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=16770
Printed Date: 19 Jan 2025 at 5:27pm
Software Version: Web Wiz Forums 12.04 - http://www.webwizforums.com
Topic: X570 Taichi PCIe working at x8 instead of x16
Posted By: Blacksun1
Subject: X570 Taichi PCIe working at x8 instead of x16
Date Posted: 07 Oct 2020 at 4:41am
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Hello So I've recently noticed that my x16 PCIe bus is working only at x8 lanes (I'll link the GPU Z image bellow). I've updated my BIOS to the latest version (P3.40) and loaded the default settings, I've installed the latest AMD chipset drivers, I've tried re-seating the GPU multiple times (and yes, it's plugged in the correct PCI slot) and nothing helps. I thought maybe the software is misreporting, so I've run the 3dmark PCI express feature benchmark and I'm getting around 6.5 gb/s bandwidth which really seems like only 8 lanes. I've also checked my gpu at a friends computer and there it works fine at x16, so it's not a gpu issue. I also have nothing else in any of the PCI slots besides the GPU, all the drives are SATA. I'm running out of ideas here..is the board faulty or is there something I could do in BIOS? The only PCI settings I could found there are regarding which gen it runs and those do nothing. The rest of my specs: Ryzen 3700x GTX 1070 ti 16 gb DDR 4 Fractal Ion 760p PSU Samsung EVO 850 SSD, WDC HDD, both SATA connected Any help would be much appreciated  (It also shows the PCI as 3.0, I assume that's normal as the gpu is 3.0) |
Replies:
Posted By: Blacksun1
Date Posted: 10 Oct 2020 at 4:34am
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Zero replys here and on my support ticket. Great tech support guys.. |
Posted By: Xaltar
Date Posted: 10 Oct 2020 at 5:19am
The forums are not tech support  That said, ASRock Tech Support does often post here and check on things.I take it you are using the top most PCIe x16 slot? If not, that is your problem. The lower slots are wired as x8 and x4 respectively. While the slots are physically x16 they are not wired that way. Only the top PCIe slot is capable of x16. As for the PCIe generation showing as 3.0, you are correct, it is limited to the generation supported by your GPU. ------------- 
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Posted By: Blacksun1
Date Posted: 10 Oct 2020 at 6:52am
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Well, I did submit my problem via the support request form on the website five days ago and haven't gotten a word yet.. Yes, I'm using the top slot. |
Posted By: Xaltar
Date Posted: 10 Oct 2020 at 1:36pm
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If you click the little "?" next to bus interface it should start a render test that will load the GPU enough to trigger it out of power saving. Does the link width change when you do this? (PCIe x8 should become x16). -------------
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Posted By: Blacksun1
Date Posted: 11 Oct 2020 at 12:45am
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Nope, stays the same. That's what I've tried first. Like I've said, I even tried the 3dmark PCI bus test and it really looks like the gpu works with 8 lanes, even in full load. |
Posted By: Xaltar
Date Posted: 11 Oct 2020 at 2:51am
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Ok, so the next step is to remove the GPU and clean the contacts, I usually use isopropyl alcohol and a cotton bud. Make sure they are all shiny and clean with no residue. You can also check inside the slot and make sure there is no debris in there. Once you have done that, make sure you install the card all the way into the slot. If the back end is not all the way in you will lose PCIe lanes to the GPU. PCIe x1 is the first section of the slot (matching the PCIe x1 slots) then x4 is the next collection of pins etc all the way moving outward to the back end of the slot to PCIe x16. This is the most common cause of limited connection width, the card not being fully seated. Good luck and let us know if it resolves the issue. -------------
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Posted By: Blacksun1
Date Posted: 11 Oct 2020 at 5:39am
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I've tried removing and re-seating the GPU several times. I've cleaned the connectors on the gpu but I haven't tried using alcohol so far. They seem really clean and I've already tried it out in my friends computer where it worked without issues, so I'm pretty sure that's not the problem. It's also placed firmly and stable in the PCI slot. I haven't really looked if there's anything inside the slot, but it's a relatively new board, it didn't really had the chance to gather dust and stuff inside it.. Though I guess I could examine it more carefully. Thanks for helping :) |
Posted By: Blacksun1
Date Posted: 11 Oct 2020 at 6:59pm
| Ok, tried cleaning and examining everything. Still no luck |
Posted By: Xaltar
Date Posted: 12 Oct 2020 at 10:25pm
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That is very odd. Are you sure the lower portion of the card is slotting in all the way and the card's cooler isn't fouling on something? The end furthest from the rear IO. If you have the option, try testing a different GPU and see if that gives you a full PCIe x16 connection. -------------
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Posted By: Blacksun1
Date Posted: 14 Oct 2020 at 3:03am
Quite sure. I have an old gtx970 lying around somewhere, I can try it out. I'll report the results |
Xaltar wrote: