Attempting to lower the PCI lanes to x4 (if this is my problem)

[Nosnibor]

Hello. I am attempting to get my GPU to run at less lanes in order to get some other cards to run on PCI (non-gpu). It seems that my main issue may be to limiting of CPU lanes.

 

So what happens is if any other cards are in their PCI slots the GPU does not get recognized by Windows. I'm thinking it has to do with lanes but I am not 100% sure. Ideally I would love to get my GPU and 3 of the other cards running all at x4 but I am not sure if that is possible. So here are my system specs:

 

ASUS WS Z390 Pro

Intel i9 9900k

EVGA RTX 2080ti

EVGA 1000W PSU Gold

G.skill Ripjaw 64GB RAM

2x Blackmagic Deck Link Duo 2

Blackmagic HDMI Recorder

 

The PCI lane chart for my mobo is semi confusing so I am not sure where to slot things for the configuration I am trying to achieve if even possible. I have not tried a single extra card yet and seeing if that will work (out of the office so I am doing brainstorming).

 

Please let me know if I can add any additional information!

 

Thanks.

 

Edit: The BIOS is recent at 0701 and I was able to get the most recent NVIDIA and Blackmagic drivers installed.

[KarathKasun]

Use the x16 slots, it should split to x8/x8/x8/x8.

[Windows7ge]

Your CPU only has 16 lanes but you should have 40 available as the Z390 chipset contributes 24. So you have plenty to go around...

[Nosnibor]

8 minutes ago, KarathKasun said:

Use the x16 slots, it should split to x8/x8/x8/x8.

 

5 minutes ago, Windows7ge said:

Your CPU only has 16 lanes but you should have 40 available as the Z390 chipset contributes 24. So you have plenty to go around...

When any other PCI device is plugged in the GPU stops being detected by Windows. So this is where I am getting lost.

[Windows7ge]

3 minutes ago, Nosnibor said:

 

When any other PCI device is plugged in the GPU stops being detected by Windows. So this is where I am getting lost.

The board looks like it's designed to hold up to four cards in that configuration. Did you try connecting the extra 6-pin on the motherboard?

[KarathKasun]

Make sure you do not have VM features turned on in the BIOS if you are not using them.  It could be splitting the devices out for virtualization.  Another thing that can happen is that one of the cards is using system resources that overlap with the GPU.

 

I assume that the GPU is in the topmost slot?

[Nosnibor]

2 minutes ago, Windows7ge said:

The board looks like it's designed to hold up to four cards in that configuration. Did you try connecting the extra 6-pin on the motherboard?

All power should be in but I will double check.

[Nosnibor]

1 minute ago, KarathKasun said:

Make sure you do not have VM features turned on in the BIOS if you are not using them.  It could be splitting the devices out for virtualization.  Another thing that can happen is that one of the cards is using system resources that overlap with the GPU.

 

I assume that the GPU is in the topmost slot?

It currently is however I wasn't in the office when things arrive and someone else built it and powered it up first. They installed the GPU in 4th PCI slot (after the 4x slot) and I wonder if some initialization screwed with that? They weren't seeing the GPU. Once I removed everything and tried just the GPU in the top slot alone it was found and I was able to install drivers.

 

I will also research "VM features" and see if I can find that setting int he BIOS. In your second thought what would be a potential work around?

[Windows7ge]

2 minutes ago, Nosnibor said:

All power should be in but I will double check.

Normally the extra 6-pin isn't a requirement but if you are plugging in a pile of power hungry equipment you might need it.

[Nosnibor]

1 minute ago, Windows7ge said:

Normally the extra 6-pin isn't a requirement but if you are plugging in a pile of power hungry equipment you might need it.

Could this be the 6 pin right by the PCI slots? I know I have the dual 8 pins at the top of the board plugged in.

[Windows7ge]

1 minute ago, Nosnibor said:

Could this be the 6 pin right by the PCI slots? I know I have the dual 8 pins at the top of the board plugged in.

Yep. The current PCI_e standard I believe only allows up to 75W so sometimes with 3~4 GPU's they need a few more wires off the PSU than the 24 pin.

 

If you only have 1~2 GPU's and those other cards don't consume much then it probably won't do anything for you. I'm just offering up ideas right now.

[KarathKasun]

5 minutes ago, Nosnibor said:

It currently is however I wasn't in the office when things arrive and someone else built it and powered it up first. They installed the GPU in 4th PCI slot (after the 4x slot) and I wonder if some initialization screwed with that? They weren't seeing the GPU. Once I removed everything and tried just the GPU in the top slot alone it was found and I was able to install drivers.

 

I will also research "VM features" and see if I can find that setting int he BIOS. In your second thought what would be a potential work around?

Disable VT options in BIOS.  Also, GPU goes at the top.  The initialization order is tied to the slots physical location and the GPU needs first dibs on resources, the other cards are not as strict on what resources they need to work and can go in the other slots.

 

As for the 6-pin, its a PCIe connector like what gets plugged into a GPU, and you may need it connected for that hardware.

[Nosnibor]

6 minutes ago, Windows7ge said:

Yep. The current PCI_e standard I believe only allows up to 75W so sometimes with 3~4 GPU's they need a few more wires off the PSU than the 24 pin.

 

If you only have 1~2 GPU's and those other cards don't consume much then it probably won't do anything for you. I'm just offering up ideas right now.

Not sure what the GPU is drawing off the top of my head but each of the Blackmagics SDI require 10W and the HDMI requires 23W.

[Nosnibor]

7 minutes ago, KarathKasun said:

As for the 6-pin, its a PCIe connector like what gets plugged into a GPU, and you may need it connected for that hardware.

So I should use one of the "VGA" ports on the PSU for that 6 pin. I have 4 I believe.

[KarathKasun]

Just now, Nosnibor said:

So I should use one of the "VGA" ports on the PSU for that 6 pin. I have 4 I believe.

Correct.

[mariushm]

The board has a PLX 8747 chip that's like a network switch for pci-e lanes... it takes the 16 pci-e lanes from cpu and makes a bunch more lanes.

 

 

So you have :

1PCIE 3.0 x16_1 slot

2PCIE 3.0 x16_2 slot (max. at x8 mode)

3PCIE 3.0 x4_1 slot (max. at x4 mode)

4PCIE 3.0 x16_3 slot

5PCIE 3.0 x16_4 slot (max. at x8 mode)

I'm not sure which slots are all merging into the x16 lanes from cpu, so I wouldn't know what to tell you, but anyway.... no matter where you plug cards you have at least 4 pci-e lanes and your cards don't use more than 4 lanes.

In addition to that, there are adapter cards you can buy which can convert an M.2 connector into a pci-e x4 slot... if you need an extra pci-e x4 slot

 

[Nosnibor]

21 minutes ago, KarathKasun said:

Make sure you do not have VM features turned on in the BIOS

 

9 minutes ago, KarathKasun said:

Disable VT options in BIOS.

Is there a difference or both?

[Windows7ge]

Just now, Nosnibor said:

Not sure what the GPU is drawing off the top of my head but each of the Blackmagics SDI require 10W and the HDMI requires 23W.

Well that blows my theory out of the water. Nevermind. It won't help. I'm not sure where to look next right now. I'll let you know if I think of anything.

[KarathKasun]

3 minutes ago, Nosnibor said:

 

Is there a difference or both?

VT-x and VT-d are the ones I remember off the top of my head, those are Intel virtualization extensions.

 

First and foremost, put the GPU in slot number 1, the one closest to the CPU.  Slot 5, the one at the bottom runs through the chipset and can cause problems for a GPU in a fully populated system that has only one GPU.

[Nosnibor]

5 minutes ago, Windows7ge said:

Well that blows my theory out of the water. Nevermind. It won't help. I'm not sure where to look next right now. I'll let you know if I think of anything.

 

Well doesn't the GPU pull more than 75W? Or does it any type of reservation because it can? Because I am asking for 43 more...

[Nosnibor]

45 minutes ago, Windows7ge said:

Your CPU only has 16 lanes but you should have 40 available as the Z390 chipset contributes 24. So you have plenty to go around...

Sorry to bring this back from the past but can you help me understand the board lanes or know where I can go to learn about it?

[Windows7ge]

1 minute ago, Nosnibor said:

 

Well doesn't the GPU pull more than 75W? Or does it any type of reservation because it can? Because I am asking for 43 more...

The GPU gets dedicated power from the PSU via 2x 8+2-pin cables. It's just that it can draw up to an additional 75W from the board itself if it needs it.

[KarathKasun]

9 minutes ago, Nosnibor said:

Sorry to bring this back from the past but can you help me understand the board lanes or know where I can go to learn about it?

Slots 1 and 2 connect directly to the CPU.

 

Slots 4 and 5 connect to the chipset.

 

You want to use the CPU connections first for GPUs, and the first slot in this layout is generally the direct to CPU PCIe lanes.  If you use 1 and 2 it gets split to x8/x8.  Likewise, the x16 from the chipset is slot 4 and it gets split to x8/x8 when 4 and 5 are in use.

 

Slot 1 is where the manual says to put the GPU, so that is absolutely where the direct CPU connection is.

 

[Windows7ge]

4 minutes ago, Nosnibor said:

Sorry to bring this back from the past but can you help me understand the board lanes or know where I can go to learn about it?

Well, you can find the CPU on Intels .ark website: Intel i9-9900K

Looking down the page you find how many PCI_e lanes it supports.

 

As for your chipset you can also find the their .ark website: Intel Z390

This gives a lot of information about the chipset including how many PCI_e lanes it supports.

[Nosnibor]

6 minutes ago, Windows7ge said:

Well, you can find the CPU on Intels .ark website: Intel i9-9900K

Looking down the page you find how many PCI_e lanes it supports.

 

As for your chipset you can also find the their .ark website: Intel Z390

This gives a lot of information about the chipset including how many PCI_e lanes it supports.

I guess I was asking about how it works. I was assuming it was like "the board is capable of X lanes but the X is determined by the CPU" but you're saying the lanes from CPU and MOBO are separate and add to the total amount of lanes available?