SSD M.2 with PCIe 4x adapter not detected in bios

iteration

Prominent
Sep 28, 2017
1
0
510
Recently decided to purchase an SSD (Plextor M8Pe, M.2 NVMe SSD PCIe 3.0 x4 with 1T) but didn't notice the format M.2 cannot be plugged directly onto my ASUS P8Z86-V PRO/Gen3 Motherboard.Thus I bought an X4 PCI Express to M.2 PCIe SSD Adapter to plug it on my board.

I noticed I have an PCIe 2.0 x16 slot that is compatible to run x4 and x1 modes to be used with PCIe x1 and x4 devices and I read somewhere that running a PCIe 3.0 device on a PCIe 2.0 would only cause lower performance. So I thought I was grand.

However I cannot find it in my BIOS nor when I boot from Windows Installation device. Strangely enough it shows up with a Plextor screen during booting (illiterate AF here), so it somehow recognize the drive but it just wont show.

I already have a GPU plugged in at my PCIEx16_1 and tried plugging the adapter into PCIEx16_3 (the black one) so it shouldn't be a case of shared bandwidth.

I already run 2x HDDs in my SATAs - don't think it matters in this case but just in case.

Anyone could provide me some tips or answers?

Quick access to specs:
Motherboard: ASUS P8Z68-V PRO GEN 3
http://www.cizgi.com.tr/upload/pms_dosya/287/e6850_p8z68-v_pro_gen3.pdf

Plextor P8Pe, M.2 NVMe SSD
https://www.newegg.com/Product/Product.aspx?item=N82E16820249087

StarTech X4 PCI Express to M.2 PCIe SSD Adapter
https://www.startech.com/HDD/Adapters/pci-express-m2-pcie-ssd-adapter~PEX4M2E1
 
Solution
You cannot boot from that m.2 drive in that motherboard.
No matter how it is connected.

A regular SATA III SSD will work no problem.