Don't know.
I didin't tested multiple boards, also don't know if other x16 M.2 cards develop this issue.

I don't see the issue here? And, I think from others testing, all Asus X79 can use only x3 NVME's (not x4, and not limited to only x2 either for sure)
@JackSted or @paranoid_android will be able to tell you how to setup and use x3 NVME, I think they both tested this, I thought @agentx007 did too but maybe I'm mistaken?

The ASROCK 4x adaptor card I'm using seems to have a similar problem BUT I think it could be down to if you use a BOOT drive as one of the drives in the 4x Adaptor cards... I had real trouble with my cards. However, picked up a cheap adaptor PCIE-3 M2 adaptor card card and slapped it in the 3rd PCI-E 8x slot as the boot drive keeping the 5700Xt in the top slot, the ASRock 4x Adaptor in the 2nd PCI-E slot down. I've then put the 2nd NVMe card into the ASRock 4x M2 adator for now as I ain't got time to fiddle around, but I really think it's a problem with assigning BOOT as the boot manager disappears. I think that if I was to fill these adaptors now with NMVe it'll pick them up right away as long as they're all just storage devices. However, because it's expensive I won't be for now hahaha.

@Lost_N_BIOS I wasn't able to use 3 or more NVMe drives out of my ASUS M.2 x16 card (v2 version).
BUT you can use more than 2 NVMe driver, IF you have a second M.2 adapter/card on different PCIe slot.

Thanks guys - all of you - for your input. It seems to be rather MOBO's chipset limitation then. Or it's implementation done by ASUS. This is no good for me, because if you check out my screen shot of HWINFO I have all slots occupied, except 1xPCIe x1 2.0 - which is useless.
So time to move on other MOBO which has one more 16x mechanical slot (4x would be sufficient because I do have an cheap Gembird adapter of PCIe x4 for single drive.
The new MOBO I do consider is GIGABYTE GA-X79-UP4. I wonder whether it has moded NVMe and bifurcated BIOS already...

@Jerzy - X79-UP4 all Bifurcation settings are in hidden debug folder (MIT >> System Info >> No-Named folder) in AMIBCP, you can change them from there, but they can't be made visible in BIOS, only two IOU's offer 4x4x4x4x
I can make you NVME mod BIOS for that system, if you end up getting the board let me know

Zitat von agentx007 im Beitrag #304

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@Lost_N_BIOS I wasn't able to use 3 or more NVMe drives out of my ASUS M.2 x16 card (v2 version).
BUT you can use more than 2 NVMe driver, IF you have a second M.2 adapter/card on different PCIe slot.

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I was wondering if could be the sabertooth x79 modded to have all turbo cores like here: https://www.youtube.com/watch?v=n70kVysF...ndex=22&t=1212s

Zitat von Pugheaven im Beitrag #307

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Did you get two running on that Asus car mate? Also, were they both data or was one of them boot as well?

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Zitat von agentx007 im Beitrag #309

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Zitat von Pugheaven im Beitrag #307

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Did you get two running on that Asus car mate? Also, were they both data or was one of them boot as well?

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Yes I did. One did boot, while the other one was data.
They can both be used with CSM enabled as well. Which needed EFI support on PCI-e devices to be enabled, and UEFI as primary boot mode. If you don't need CSM, just disable it (requires GPU with EFI vBIOS).
Also, it's worth shutting down MB itself, and not just restarting it :
Sometimes drive wasn't detected after BIOS setting change, and shutting down board and then powering it on again always solved it for me.

Crucial thing for x16 card is which M.2 ports you use (since not all of them are available), in my case :
1-st one to work is always the top one (or the one furthest from PCI-e slot on M.2 x16 ASUS card).
2-nd to populate, is the third one from top (or second one if you count from PCI-e connector up).

@gdfath3r Isn't that redundant with low-ish priced overclockable Xeons around X79 platform ?
I know you can get 12 Core Ivy, but at 3,5GHz is this really better than 4,3GHz 1680 v2 ?

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Zitat von Pugheaven im Beitrag #310

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@agentx007 - Brill so based on that, it's slots 1 and 2 on the ASUS that work which is interesting based on the ASUS layout.

ASUS CARD PICTURE

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Zitat von Pugheaven im Beitrag #303

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The ASROCK 4x adaptor card I'm using seems to have a similar problem [...]

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@agentx007 I have an 8 core E5-2667 v2 which turbo's @4.0 ghz. I dont think worth replacing with E5-1680 v2 since in not too much difference. I would be more happier if the bios can be modded tho. The E5-1680 v2 still hard to come by, and my cpu reaches a respectable speed at default, so I believe it justifies ( moneywise) a good mod.

Zitat von agentx007 im Beitrag #311

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[quote=Pugheaven|p110782]
@agentx007 - Brill so based on that, it's slots 1 and 2 on the ASUS that work which is interesting based on the ASUS layout.
[...]

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Zitat von Lost_N_BIOS im Beitrag #306

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@Jerzy - X79-UP4 all Bifurcation settings are in hidden debug folder (MIT >> System Info >> No-Named folder) in AMIBCP, you can change them from there, but they can't be made visible in BIOS, only two IOU's offer 4x4x4x4x
I can make you NVME mod BIOS for that system, if you end up getting the board let me know

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