second gpu via pcie x1 to x16 riser only mines 4 mhs

hi guys thanks beforehand because i know you will help me


i have one rx 470 sapphire ref working at 26.7 mhs on the pci express normally.

i have another exactly the same: both sapphire ref and both working at around 26.7 mhs (if used one at a time)

the problema is as soon as i use a pcie riser, and put the second card to make them both work together, that secon card gives only 4mhs on claymore.

also when i try to see it with gpuz it says it runs at 0 MHz core and mem.

when i open wattman, all possible options on the second video card are grayed out.

if i try to open atiflash, it shows an error: failed to read rom and atiflash wont start.


but as soon as i remove the gpu and put it as a solo on the pcie x16, both card Works separated, wattman can read them, and also, atiflash can open.


any help?

thank you very much