PCIe / Wifi module / GPU conundrum

[craighazan]

Sort of stumbled across this conversation so forgive me if I bring something up that’s been mentioned already. Have you tried an NGFF (M.2 E Key) adapter?. I have tried different variations of this setup with out much luck so far.
@c-o-pr the NGFF/M.2 E Key can be used for WiFi/BT and GPU’s!.
@phunguss might be able to help with this.

 

[Bergier3K]

@craighazan Thanx for chipping in, yes that is the option I will investigate.

For general info, I found the thread mentioning that Gigabyte CNVIs are whitelisted for Intel only, it is post #2 from @UtterDisbelief.

 

[Edhawk]

The PCIE x4 slot will have an option in the bios for how it is to be configured. It might be disabled in favour of the 3rd M.2 connector.

I assume from your comment above that you don’t have 3 x NVME drives connected.

 

[Bergier3K]

@Edhawk I have only 2 for now slot #2 with the main Macos drive, slot #3 with a spare 960evo for Macos update testing, nothing slot #1. Though, I'm right now in the process of changing that. It will ideally be : #1 windows and #2 Macos, the 3rd slot will be empty or populated only for testing.

I have flashed the bios to the latest version and no option for the x4 slot is available. Regarding PCIe I have only 2 options : choice for bifurcation and choice of Gen for the CPU slot (in case of an 11th gen CPU with a gen4 GPU). Though there might be something to try : Wifi/BT in the PCIe x4 and 3rd m.2 slot empty.

@Edhawk Just checked the manual and PCIEx4 is reduced to x2 when the #3 m.2 slot is populated, so it still should work (it needs just x1).

 

[c-o-pr]

Just checked the manual and PCIEx4 is reduced to x2 when the #3 m.2 slot is populated, so it still should work (it needs just x1).

You checked about SATA influence too? There's a common config edge where higher SATA ports compete with last M.2 slot. So if you have a SATA drive plugged it into a high number mainboard port (even just one) you may lose access to the last M.2 slot.

I don't know the details of the board you're using. EdHawk might know.

 

[Edhawk]

From what I read the 6 x SATA ports are not sharing bandwidth with the M.2 connectors.

It is just the bottom PCIe slot x4 and the M2P_PCH connector that share 4 x PCIe lanes/bandwidth. When both are populated they both step down to x2 PCIe lanes. If only one is used it retains the full x4 PCIe lanes/bandwidth.

@Bergier3K have a look in the System Bios, specifically at the following:

Settings > IO Ports > PCIE Bifurcation Support, as this controls how the 3 x PCIe slots behave, see below.





If you want to use the bottom PCIe slot for the WiFi/BT card, then you need to use the x8/x4/x4 option not Auto or x8/x8, as these last two might leave the bottom PCIe Slot inoperable.

 

[Bergier3K]

@Edhawk Thanx for looking into it. Its is getting night here but I will try your suggestion tomorrow morning first thing. I had tried x8/x8 and auto, but not x8/x8/x4, thinking naïvely that auto would be the best course of action...

As info, here are 2 screens of the manual, elaborating a bit more about how the pcie lanes and m.2 slots behave...

Thanx again ! I hope to report a success tomorrow morning

 

[Edhawk]

For a Z490 board with the name 'Extreme' the only thing I think that is extreme is the way they have crippled a lot of the standard features! Most boards can provide 8x/8x/4x to the three x16 PCIe slots, with a couple of x1 slots alongside the x16 slots, plus 2 x M.2 PCIe connectors.

Looks as though they have passed the missing 4 x PCIe lanes from the graphics to the Thunderbolt device and the x1 slot PCIe lanes to the third M.2 connector. Adding the TB device and third M.2 connector without increasing the number of lanes available seems criminal.

Are you even using the Thunderbolt device?

Hope the x8/x4/x4 setup works.

 

[Bergier3K]

@Edhawk I understand, but it's a really good motherboard, it feels quite durable (which was my main concern) and it was available. The availability of Z490 boards here is quite bad, the distributors moved quite quickly to more recent chipsets.

I'm not using Thunderbolt now, but planing to, again the board was intended to be long lasting and versatile.

As for the x8/x4/x4, well, it didn't work. Nothing even recognized by the Bios. I was thinking that pins setups in PCIe slots must follow a specific standard, otherwise compatibility would be a nightmare. So why would the card work in slot 1 and not slot 2 ? A hardware problem seems out of the picture (unless PSU problem, which I will test beginning of next year) and I'm wondering how a software problem would happen before the BIOS, that makes little sense to me (not an engineer though)...

 

[Edhawk]

I would check the three PCIe slots to make sure they all work individually as well as in combination with at least one other slot. I would undertake the testing with another PCIe card (USB PCIe x1/x4 or similar), as the x8/x4/x4 bios option should enable all three PCIe slots.

Do you still have the 3rd M.2 slot occupied with an NVME drive? As that might prevent the bottom x4 slot from working, as the two share the bandwidth. It would all depend on how the system has been configured by the manufacturer. The bottom PCIe slot is supposed to work at x2 speed when an SSD M.2 drive is present in the 3rd M.2 connector. It says nothing about the bandwidth being shared when a PCIe NVME drive is present.

It is highly unlikely to be a PSU issue, assuming you have a reasonably sized PSU, i.e. 550W or larger.

A software issue would not happen before the Bios process, as it doesn't become active till the Bios has finished its work.