Hi,
You are running high speed testing here which means SI design is critical design consideration to evaluated properly.
- Have you isolated the link down is caused by higher BER ? Then likely this is due to SI issue
- Have you perform SI analysis sim on your side ?
If Intel ship you bad cable then you can make request to complaint for replacement but now my understanding is the other way around. Other brand cable is not working here.
- is my understanding correct ?
Thanks for the isolation test. This proven your cable is not broken. Then it could be due to cable performance issue here.
- Have you try out other brand cable ?
- Try out shorter length cable ?
- Study the data sheet spec between different cables to watch out on insertion loss and return loss impact ?
If your overall system transmission link doesn't have much margin left then higher insertion loss/return loss could eat up the margin and caused link down.
Thanks.
Regards,
dlim