I think method B is a lot less risky and that's the one I use for all of my rigs.
But I don't have (obviously
) a deep understanding of this so also interested in others' opinions.
Method A : "It is risky to supply the motherboard and some risers with differents PSU. But supplying a GPU and his Riser with differents PSU is ok"
I don't think that the motherboard has any reasons to care about how you powered the risers. You only connect them together with the data cables ("usb"), it's a very low-power connection as far as I know. A gpu, on the other hand, can draw up to 75W from the riser, and a lot more from the extra 6/8-pin pci-e connectors, so it might not like the power coming from different sources. But I don't have (obviously
) a deep understanding of this so also interested in others' opinions.Make sense to me. Still a lot of people doesn't agree
(https://www.reddit.com/r/EtherMining/comments/6k56fv/housefire_warning_do_not_used_2_power_supplies/
https://bitcointalk.org/index.php?topic=1843586.msg18351224#msg18351224
https://bitcointalk.org/index.php?topic=1761303.msg17825999#msg17825999
https://bitcointalk.org/index.php?topic=443540.msg4878774#msg4878774
https://www.youtube.com/watch?v=pQ-EAunoAqY&t=494s around 7:15
https://miningstore.fr/fr/accueil/15-coupleur-alimentation-similaire-add2psu.html a shop site saying "Warning: do no connect motherboard or risers to the secondary PSU")
Edit: https://forum.ethereum.org/discussion/7533/its-friday-night-rig-time This, especially, is interesting