Can we connect PCIex4 card in PCIex16 slot?

Solution 1:

We contacted HP, they answered that they did not know why. they said that they did not test this PCIeX4 in particular. They did not know how to help, neither where the problem could come from.

This extension PCIEX1 to PCIEX4 is making the job, probably 4 times slower, but luckily, the speed is not critical in this application

https://www.amazon.com/GLOTRENDS-Extension-Limited-Installation-UEX105/dp/B07N39KWHZ/ref=pd_di_sccai_2/143-3411009-1910802?_encoding=UTF8&pd_rd_i=B07N39KWHZ&pd_rd_r=1d43f406-facf-4ba2-9ca1-6c74184cb052&pd_rd_w=VLA82&pd_rd_wg=42p3E&pf_rd_p=c9443270-b914-4430-a90b-72e3e7e784e0&pf_rd_r=4C2E1HW0J48FQ9A0CZPK&psc=1&refRID=4C2E1HW0J48FQ9A0CZPK