The following is an outline of my problem and the information I sent to Silverstone;

I have a desktop with Ubuntu Mate 18.04 installed on its own SSD-HDD combo and windows 8.1 on a separate SSD-HDD pair. The motherboard is an Asrock Z87 Pro3 with 16GB ram and an I5 processor, it has a 650w PSU and no GPU.

I have installed a Silverstone SST-UCU01 expansion card, it works out of the box with Windows 8.1 and Ubuntu Mate 18.04 and the speeds look to be about the same as the motherboard 19 pin header, I have the SST-UCU01 in the PCIe2 slot (it is PCIe 3.0), but there is a problem...

I have 2 removable drive bays in this desktop (a Enermax EMK5201U3, and a Sharkoon SATA Quick Port), when either of the bays power is switched on the Silverstone card causes the computer to reboot within 3-4 seconds of being shut down but when the drive bay(s) power is switched off, everything works as expected in Windows and Ubuntu.

I have tried different connection combinations and have found that without any other connections to the card (I.e. SATA power and USB 19 pin headers) and with the Motherboard 19 pin header removed the problem is caused by inserting the SST-UCU01 in the PCIe slot.

The Silverstone people responded with the following;

Please kindly check following settings in your BIOS:

PCIE Standby power

USB Standby power 

Both options need to be set to ?�disable??/span>

How do I do that, I have looked in the BIOS and cant see anything that looks like the PCIE Standby and USB Standby power options?

Thanks.