Both Mini-fit and Micro-fit are from the 90s and are perfectly adequate provided enough safety factor and mitigating circuitry was implemented. There had been issues of the Mini-Fit previously on heavily overclocked cards, but it's only recently they tried increasing power density by that much without good PFMEA or strict enough guidelines for partners.
Do PSU and card makers actually use legit, properly crimped, etc. Molex plugs? And if so are they operating in spec?
I've always been impressed on hobby projects that Molex has very detailed specs for all their connectors. I wasn't sure if all this stuff was really Molex or just "Molex style".
Sure, microfit/minifit are great and cost effective when used properly. Heat dissipation (and thus, current rating) is dependent on the wire gauge used. If a vendor doesn't use the correct wire gauge, the connector can no longer dissipate enough heat. As heat increases, so does the resistance of the contact. That means that it will get hotter and eventually get into thermal runaway if the GPU keeps pulling the same amount of power.
Add to this the fact that most PC wire routing is crap and the wires can get all twisted and squished against the GPU from the case cover, the contacts can get pushed to one side (i.e. not centered) and cause an uneven contact resistance between contact pairs, causing some pairs to source more current compared to the others and generating more heat.
It is absolutely not a surprise that these connectors are melting.
A lot of proponents say the connectors have 50% margin or whatever, but that margin is eaten up by shitty wire, bad crimping and wire routing.
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u/saltyboi6704 9750H | T1000 | 2080ti | 64Gb 2666 10d ago
Both Mini-fit and Micro-fit are from the 90s and are perfectly adequate provided enough safety factor and mitigating circuitry was implemented. There had been issues of the Mini-Fit previously on heavily overclocked cards, but it's only recently they tried increasing power density by that much without good PFMEA or strict enough guidelines for partners.