Gigabyte Z97 Gaming GT: PCIe slots 3.0 that working only at 1.0 with an ASUS Hyper M.2 x4 expansion card

[Myrmeleon]

Hi all,
i have a little problem with my PCIe 3.0 port!
In my motherboard dont there are m.2 slots, for this reason i have buyed an Asus Hyper m.2 x4 (PCIe 3.0) card for install a Samsung nvme 960 evo 250 gb.
I have installed my Win 7 64 bit on this drive and installed also the newest Driver Samsumg nvme but Samsung Magician software tell me that the nvme are working to 4x but in mode gen 1.0 instead 3.0...
In fact the benchmarking are very poor (900 Mb/s write and read).
I have proved to change the location of the expansion card in all slot pcie 3.0 (both 8x, 16x), the first in occuped from my vga card (1060 GTX), but nothing!
I have selected manually in Bios option gen 3 for pcie slots but nothing...
I have also upggrade the Bios from version 7 to 8a but nothing...
Any solutions for fix this problem?
My config:
Gigabyte z97x Gaming Gt
16 Gb DDR3 Patriot Viper 3 2133 Mhz
GTX 1060 6 Gb
SSD Sata Samsung 840 EVO 120 Gb
SSD Sata Kyngston Hyperx 120 Gb
HD Western Digital Caviar Blue 500 Gb
Networking card i210-T installed in a Pcie 1x slot
OS: Windows 7 64 bit Enterprise SP1
Thanks all for support!