pcie problem: number of assigned data lanes randomly changes

[flowgeek]

Hi all,

I have the folloing problem: I have a Z4G4 W-2125 which i want to use as a Data Aquisition System for a high speed camera.

The data aquisition card of the camera needs 4x speed.

When i freshly install the DAQ card into the PC i get the 4x speed. But rather randomly when i reboot the PC it only gets 1x assigned . Sometimes i get the 4x back - but i have not yet figured out if it requires a "cold start" or a reboot. it seems very random...

when i run cpu-z to get some more info it is listed as "1x (4x max)"

--> so i guess the system sees it properly? but why does it not get the 4 data lanes assigned?

i've checked in the BIOS, but i cannot force an assignment. 

I also 

- deactivated the power saving options for the pcie bus in BIOS and Windows - does not change anything.

- deactivated windows fast boot

- disabled all pcie ports which are not in use

Is there any other way to make sure i get the 4 lanes always assigned?

a bit on the system configuration - if it helps:

- p4000 graphics card installed in slot 1

- HP Z Turbo Drive Quad Pro with 2 ssd installed in slot 3

- the DAQ card is installed in slot 5

slot 5 is listed in the manual as follows:

PCI Express Gen 3 x8 (from CPU)

but i get the same behaviour if i put it in slot 4 (PCI Express Gen 3 x16 (from PCH) )

is this a known issue? (i have not yet updated the BIOS)

thanks