Soldering is not the correct solution for high power/current applications. Car manufacturers openly instruct "do not solder, use included crimp connectors" for fuel injector wiring repairs for example.

This is because soldered connections not suitable for applications subject to vibration or repeated motion. They will weaken and break. For stationary applications, soldered connections have superior electrical characteristics.

I'd be wary about extrapolating from cars or other vehicles: they expose their components to far more vibration and shocks than is typical in a house or datacenter.

Counterpoint: cars don't get their cables moved about so often, or bent at sharp angles for aesthetic reasons. Soldering without additional strain relief is a terrible idea - even for low currents.

car cables move all the time when cars are driving.

I never said they don't - rereading, I should have used the word "manipulated", because I meant "moved (by a person)": a PC[1] gets opened more frequently often than a car hood.

1. Especially a pc with an RTX 40X0 card - because only enthusiasts are buying them at this point.

As an HPC system administrator who also works on hardware, I'd say that the servers' life are equally hard from power and temperature perspective. Their life is not easier because they are not vibrating.

A server under max load 7/24/365 is really testing its design limits.

Sure, but vibration affects solder joints in a way that a server at max load doesn't.

Then it might be a bit alarming to you that the connector itself is soldered to the board.

The issue is how to best secure stranded wire to a terminal, not how to secure the terminal to the PCB. Soldering is obviously preferred for the latter case, but when dealing with stranded wire, a good crimp is actually better than a good soldered connection. Done properly, the crimp forms a cold weld that's as close to a perfect connection as you can make.

Soldering can work well too, but there are so many things that can go wrong. Heat can deform the connector housing, lowering the contact pressure. Solder might run down the connector and coat the contact surface, making it unreliable over time. It might also wick down into the insulated portion of the wire, turning what should be a flexible part of the interconnect into a reliability problem, especially in the presence of motion or vibration. Last but not least, lead-free solder complicates visual inspection, making it harder to reject bad connections at the factory.

You can make bad connections with either soldering or crimping, but all in all, crimping usually wins when it comes to cable assembly. In a production setting, it is easier to establish and enforce a high-quality process when all you need is the right crimping tool and die and a few minutes' training.

" Last but not least, lead-free solder complicates visual inspection, making it harder to reject bad connections at the factory."

I x-ray every soldering job out of the oven and off the irons where I work, and that's a TINY LED company. Visual inspections of solder joints can be very unreliable no matter which solder is used. A company making these sorts of cables should be using even a cheap $10K Scienscope at the minimum.

+1, couldn't live without my articulating-arm AmScope.

That's because crimping is a more reliable connection, mechanically. It's less likely to fail.

Solder has better electrical characteristics, but that benefit is outweighed in the field because the connections can break and fail.

> "do not solder, use included crimp connectors"

That's about vibration and bi-metallic corrosion, not current handling. Gas tight crimps solve both problems whereas solder fairs poorly. Low cost PCs can't be expected to tolerate either high vibration or the elements, so a soldered design with sufficient margin for imperfect conductors could work fine in a PC.

Way to give yourself a black eye NVidia. High power needs a margin for error and there is clearly none here.

The twelve pin power connector isn't meant for low cost PCs. It is meant for extremely high end PCs and extremely reliable server hardware.

"Low cost" here includes all GPUs hosted on ATX type expansion boards, intended for price sensitive markets. "Extremely reliable server hardware" (N+1 GPU and better) doesn't use this design. Typically in HPC systems CPUs and GPUs are mounted on planar daughterboards that bear no resemblance to conventional PC hardware: NVIDIA's HGX platform (used at AWS) for example.

soldering is a terrible idea for cables that need to flex, which is why you’ll typically only find them used in applications with major strain relief, or inside non-user-serviceable enclosures (e.g. inside an ATX PSU)

You need strain relief either way, soldering or crimping. A well soldered joint will have lower resistance than a crimped one and be more resistant to vibrations.

In most applications crimping offers better vibration resistance and better conductance. Most solder is on the order of 10x as resistive as pure copper, or more.

Welding can be better than solder or crimp, but it's uncommon except for applications like wire-bonding and battery cell termination.

In general, any application where you have a fixed end on one side and a free end on another (wire to board, wire to panel, wire to X), a crimp termination is by far the better choice.

The actual amount of contact area in a soldered joint is much higher though. The crimped joint will have the tangent of each strand on the connector, for lots of tiny little contact points. Soldering, you can take the same contact points but also add the higher resistance solder for all of the area in between, dramatically increasing the cross sectional area of the contact.

It's not fine if it's going to melt.

It will only melt if it’s either undersized or a bad joint to begin with. A properly-sized, well-made solder joint will have no reason to melt unless heated externally by something else failing.