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Comment by cmsj | Hacker News Reader

Buildzoid on YouTube has a very good response to this - he does not agree that the fault is the (still terrible) wires at the back of the connector.

His reasoning is that the melting is happening down at the pin end of the connector, not at the back, and the pins that are melting the most are the edge ones, not the middle ones.

There's about 10 minutes of critique of the various ways other people have been evaluating it, which is interesting for sure, but the meat starts here: https://youtu.be/yvSetyi9vj8?t=744

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The failure doesn't necessarily have to happen at the junctions for the junctions to be a cause. It also makes sense that the edge pins would heat up more because they're both surrounded by less mass and a likelier conduit to distribute current and heat based on the resistivity of the shown wiring.

Reminds me of the molded MOLEX to SATA adapters for HDDs that suffer from similarly shoddy wiring design and are prone to melting/fires. https://www.youtube.com/watch?v=fAyy_WOSdVc

> The failure doesn't necessarily have to happen at the junctions for the junctions to be a cause.

Indeed, it can also happen that because some connection is failing, too much current flows through the remaining ones, but this is clearly not what is happening here (because it's not the inner connectors that are melting, and also because Igor tried and couldn't replicate this). This really looks like heat from high resistance, and the outer connectors are simply those experiencing the most mechanical stress, and it's really easy for these 2-slit-connectors to get bend out of shape.

Ah yes, the classic "MOLEX to SATA? Lose your data!".

I agree, that does not make sense. There must be a problem with the connection to the pins, and I'd really like to see a close-up of the female connector on the problematic card, because if stuff gets bend there out of shape even slightly, you can quickly get high resistance.

EDIT: Watched the video further, and actually the cable has the female side and they're using 2-split connectors. Yeah, that's asking for trouble when you push 50 amps through those... Sheesh, such shoddy stuff for a 1600$ card, just incredible.

Buildzoid is great, but worth noting he has a very specific perspective which is that of a hardcore enthusiast (hence the name of the channel), and he often points that out, but here I think he ends up kinda just saying "why not just stick with the old ones", which is fine in comparison to something that sucks, but it doesn't hold up more generally for most people.

I get he may not care, but plugging four individual power cables into a GPU is a pain for consumers, and having a single connector for everything is great from the normal consumer perspective.

He eventually gives a good reason for it. The old cables have a safety factor of something close to 100%, where as the current connector has a margin of 15% or so. (Going by memory here).

The takeaway being, even with a small fault in the connector, there's more than enough margin to ensure safe delivery and therefor, no molten pins or terminals.

The current connector seems to lack this, and if one of the terminals does not make a solid connection, then the drop in effectiveness is enough to push it out of spec and cause a failure.

I do greatly enjoy Buildzoid, and I was eagerly awaiting his video (and one from Gamers Nexus; note they haven't commented yet) from someone who actually looked at this from an EE perspective. I recognize his video was titled "rambling", but he largely repeated himself for 30 minutes, and scattered the relevant datapoints in the video in a few short snippets. A little planning on his delivery would gave gone a long way.

I get that, but if we can provide a safe single cable option, it's clearly preferable for a number of reasons. I don't believe this converter being badly made means the whole spec is not viable.

How often do consumers plug power connectors into a GPU for that to be a problem? Spending a few minutes routing multiple power cables for an expansion card that once installed sits in place for years doesn't seem like a big deal to me.

Clearly it's not a huge deal, but it's still preferable. Not having to route for SATA drives thanks to the rise of M.2 is often praised by people who build PCs, and it's a similar kind of deal. A new spec that is more convenient is still a selling point vs the old spec on new PSUs.

> plugging four individual power cables into a GPU is a pain for consumers

as compared to .. plugging four individual power cables into a stupid dongle?

The dongle is a short-term conversion because people have old PSUs. In the long term this standard will be built into modern PSUs and it becomes a single cable.

You have 6 pins on each row that are supposed to each have their own wire coming from the PSU. If you bend the connector and only 5 pins connect then you expect to get 5/6 of the power the connector can handle.

The adapter has connected all four wires to all six pins. Losing one of the four cables is actually irrelevant because that means less power is going into the pins. What matters is that if you are missing one pin, then all 300 watts (single row) will go through the remaining pins. Power density is now 60 W per pin. Lose another pin and you get 90W per pin over the four remaining pins. This wouldn't happen with a dedicated cable per pin.

Really seems like splitting hairs when your specifying which specific part of the cheap faulty component is "responsible".

I think we would see more problems then with this connector - while it is new to the consumer space, all of Nvidia's SXM boards use molex micro-fit connectors for power. For example my Dell C4140 has four 10-pin and four 8-pin micro-fit connections to the SXM2 board, and they are bent at 90 degrees in the 1u chassis.

I was about to post something similar but you already found something with more details.

The resistance between the male and female connectors can be much higher than what most of us have expected. While I was down the rabbit hole trying to power one of my SBC correctly, one of the findings was that the resistance introduced by the connector can go up to *0.5 ohm*(don't even mention those dodgy power supplies and cables). But even if the resistance is only 0.1 ohm, it's still a big problem as the current is for sure above 10A for a single pin, and then the heat dissipation will be over 10W, which will of course concentrated around the contacting point, which is close to the tip. This explains why the tip side was melting.

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