Getting slow PCIe 2.0 speed when using the black PCIe slot (Rampage 5 Extreme)

[Beany]

Hi everyone.

I fitted a PCIe 3.0 NVMe SSD in to the only black PCIe slot on the Rampage V Extreme (3rd slot down) and the SSD speeds are WAY lower than they should be. So i looked at Crystal Disk Info, which said the slot is running in PCIe 2.0 x4 mode, but it also says PCIe 3.0 x4 is "supported" by this slot...

So how do i change it to gen 3.0 in the BIOS for this black PCIe slot? (if it really is supported) Where exactly is the option? Because i've looked and couldn't find it. By the way, the SSD runs properly in PCIe 3.0 x4 mode when fitted in to one of the red PCIe slots, but i can't use them as they're for my GPU's. Any help is appreciated!

[BigJohnny]

Dont have an X99 but on the X299 its hiding and you have to dig

Advanced tab>System Agent>Peg port configuration
From there I can set all the PCIE to whatever I want so long as its supported.

There is nothing in the manual about it. I cant see it being any different that the X299 on this aspect anyway. Still need to be able to set those up.

[Beany]

Advanced tab>System Agent>Peg port configuration

Thanks for helping.

It's mostly the same for me, but i don't have "Peg port" in there, i instead have "DMI configuration" which seems to be the same thing. It only has a "gen 2" option though... But for all the other PCIe slots on this board that are red, they all have a gen 3 option.

So it looks like this high-end board actually has an ancient PCIe 2.0 slot (the black one). Very cheap and disappointing. Hoping i'm wrong and there's still an option to set it to gen 3 somewhere.

[jorgerod]

Hi. Only the red ones are 3.0. The black pcie slot is only 2.0 x16 not 3.0, just like the black small one is 2.0 x1 next the 3 red one. I have the rampage v extreme 3.1 with is the same board as the normal rampage v extreme. I use a Mushkin Scorpion PCIe SSD 2.0 in the black pcie. All my pcie 3.0 are in the red ones, KINGSTON SA1000 on the 2 red slot 3.0x2, Samsung SSD 950 PRO 512GB on the 3 red slot 3.0x4 both with a adapter each and a INTEL 750 400GB on the last red slot 3.0x4.
If you don´t have a free red slot you're out of luck.

[Beany]

If you don´t have a free red slot you're out of luck.

Thanks for replying.

And ah sh.... Oh well, until i upgrade soon i'll have to remove a GPU for now because i have a 2TB Addlink S70, and it's fast as a 2TB Samsung 970 Evo Plus/Pro (but without the brand price tag). So it's massively held back by gen 2 speeds.