PCI-e 16X question

[Stephg2525]

Hi i'm looking to buy the Asus Z170M-Plus.  https://www.asus.com/ca-fr/Motherboards/Z170M-PLUS/overview/

 

They got 2 16x PCI-e.

The grey one with : PCIe 3.0/2.0 x16 (x16 mode, gray) 

and the other with PCIe 3.0/2.0 x16 (max at x4 mode)

 

If i want to run SLI, my video card need a 8x slot right ? So the (max at 4x mode) mean i can't use it for SLI ? 

The 16x second slot only mean ( they can fit) but only work at 4x ?  It's gen 3.0 so i guess is not that slow. 

Im confused with this spec

 

An other question for this mobo.

Do you think the M.2 slot can work in same time of the second pci-e slot ?  

ex. SLI and m.2 ssd 

 

Sorry for my bad english hehe 

Thank's 

[Electronics Wizardy]

You need 8x for sli. You can use crossfire with 4x. Look for a sli approved motherboard.

[TrigrH]

that motherboard does not support SLI, only crossfire.

[Stephg2525]

ok thank's 

and ther M.2 slot can run in same time of the second pci-e slot ? 

ex. audio card and m.2 ssd ? 

[xentropa]

I think for that board, M.2 uses the SATA or pcie via DMI interface so it won't interfere with your video card.