by testing one card at a time you can confirm or deny that the problem is not your GPU's . if both cards don't crash testing one at a time on stock clocks then you can try running both cards at stock clocks as the next test.
so after few hours maybe around 12 hours my second card is working normal and hashing21.800 stable no crashing
does that mean i had bad riser ??
im gonna try and connect my gpu to a new riser and see or should i keep one directly to the motherboard and the other one to a riser... ?