Z170 Extreme 6 PCIe Link width / speed issues
Printed From: ASRock.com
Category: Technical Support
Forum Name: Intel Motherboards
Forum Description: Question about ASRock Intel Motherboards
URL: https://forum.asrock.com/forum_posts.asp?TID=1969
Printed Date: 18 Jul 2025 at 5:14pm
Software Version: Web Wiz Forums 12.04 - http://www.webwizforums.com
Topic: Z170 Extreme 6 PCIe Link width / speed issues
Posted By: Bellebite
Subject: Z170 Extreme 6 PCIe Link width / speed issues
Date Posted: 10 Feb 2016 at 12:45am
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Hello! First time owner of an Asrock mobo, and everything is almost under control. Thanks for the thread about installing an OS on a PCIe SSD btw. Very helpful! So my problem is, my 780 Ti link width / PCIe speed is 2X instead of the expected 16X. (I could see this using both CPU-Z and Speccy) My graphic is in the PCIE2 slot. I have an Intel 750 PCIe SSD in the slot just below. I have the latest 2.00 Bios, and speed is setup to GEN3. Has anyone encounter a similar issue? Thanks for your help! |
Replies:
Posted By: wardog
Date Posted: 10 Feb 2016 at 4:16am
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First thing I'd do here is check that the card was fully seated. Seen case interference, cables routed under the card, and the occasional flexing of the motherboard not allow it to fully seat. |
Posted By: Xaltar
Date Posted: 10 Feb 2016 at 4:46am
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As Wardog stated, make sure it is properly seated. If that does not correct it then you can check the slot for dust or debris as well as clean the contacts on the GPU. More often than not this is the cause of the problem you described. ------------- 
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Posted By: Bellebite
Date Posted: 10 Feb 2016 at 12:39pm
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Thanks for your feedback. After using my NES cart blowing skills, I am now at X8, but still not at X16... I tried two or three times, and I am stuck at X8 max now. Running out of ideas.
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Posted By: squawker
Date Posted: 10 Feb 2016 at 1:18pm
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Hi Bellebite, As you are using a PCIE slot for your Intel 750 SSD, it is using 4 lanes of a total of 16 lanes that are disponible directly from CPU, and this way the vídeo card is running at X8 (I suppose it's not possible for a Nvidia card to run in X12), so, its all OK. Only the lanes for M.2 sockets (that are via the z170 chipset) are independent from the direct lanes from CPU, that feed the PCIE slots. Regards,
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Posted By: Bellebite
Date Posted: 10 Feb 2016 at 9:17pm
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Triple Argh!! Should have been more careful!! Only way for me to get X16 on the graphic card is to get an M2 Samsung 951 then??? Thanks once again for your help.
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Posted By: Bellebite
Date Posted: 10 Feb 2016 at 9:23pm
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Or is there any way to allocate X16 for the graphic card and X4 for the Intel 750? Would performance suffer?
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Posted By: Xaltar
Date Posted: 10 Feb 2016 at 9:58pm
There is no way PCIe 3.0 x8 will bottleneck a GTX 780Ti so I wouldn't worry about it in the least  In fact I doubt the 780ti would bottleneck even at x4. Bare in mind that on AMD GPUs in crossfire the second GPU is often running at x4, even if the GPUs are R9 Furys. -------------
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Posted By: Bellebite
Date Posted: 11 Feb 2016 at 12:33am
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Thanks! I plan to get Pascal the next millisecond that thing is released, so I hope it won't be a bottleneck for this long overdue graphic card update. In this case, would you recommend that I switch to a Samsung 951 to free all the CPU PCIe lines only for the GPU? (since I am not using any from the chipset now)
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Posted By: Xaltar
Date Posted: 11 Feb 2016 at 12:41am
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I highly doubt even Pascal will fully saturate PCIe 3.0 x8 bandwidth so if you are happy with your 750 then why change it. -------------
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Posted By: squawker
Date Posted: 11 Feb 2016 at 12:23pm
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Hi Bellebite, Just one suggestion, if you are going to change your 750 SSD, despite what Xaltar said, and I think that it is a judicious opinion, change it for a Samsung 950 PRO instead, not a 951. The 951 is an OEM drive, sold without any Samsung direct support or software and it is not supported by Samsung Magician utility. Just my 2 cents... regards |
Posted By: parsec
Date Posted: 11 Feb 2016 at 3:06pm
Ignoring the X16 or x8 PCIe lane advantage or not, I agree with squawker about the 950 and an SM951. You may be finding SM951s cheaper now, but everything squawker said is true. Too bad you don't have the 2.5" version of the Intel 750 that can use a U.2 connector in an M.2 adapter card. I have that type of Intel 750 in my Z170 board, and the PCIe slot version of the 750 in an X99 board, where it belongs.  ------------- http://valid.x86.fr/48rujh" rel="nofollow"> 
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squawker wrote:Posted By: Xaltar
Date Posted: 11 Feb 2016 at 5:23pm
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I couldn't agree more about the 950 vs 951. The 950 is more polished and better featured. -------------
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