If only we had connectors which could actually handle such currents. Maybe something along the lines of an XT90, but no Nvidia somehow wants to save a bit of space or weight on their huge brick of a card. I don't get it.
12VHPWR is 8.4x20.8mm so it's got 7.7x the cross-sectional area but transmits only 2.5x the power. And 12VHPWR also has the substantial advantage that GPUs have fans and airflow aplenty.
So I can see why someone looking at the product might have thought the connector could reasonably be shrunk.
Of course, the trick USB-C uses is to deliver 5A at 48v, instead of 50A at 12v
Worth also mentioning that the same time the 12VHPWR connector was being market tested was during Ampere, the same generation where Nvidia doubled down on the industrial design of their 1st party cards.
Also there's zero devices out there that actually deliver or take 240W over USB-C. Texas Instruments literally only released the datasheets for a pivotal supporting IC within the last 6 months.
If you're saying that the connector doesn't have a 2x safety factor then I'd agree, sure.
But I can see how the connector passed through the design reviews, for the 40x0 era cards. The cables are thick enough. The pins seem adequate, especially assuming any GPU that's drawing maximum power will have its fans producing lots of airflow; plenty of connectors get a little warm. There's no risk of partial insertion, because the connector is keyed, and there's a plastic latch that engages with a click, and there's four extra sense pins. I can see how that would have seemed like a belt-and-braces approach.
Obviously after the first round of melted connectors they should have fixed things properly.
I'm just saying to me this seems like regular negligence, rather than gross negligence.
The 16-inch Framework laptop can take 240W power. For chargers, the Delta Electronics ADP-240KB is an option. Some Framework users have already tried the combination.
A few years ago there was a recall of OnePlus cables that were melting and catching fire, I had 2 of them and both melted.
But yes 240W/48V/5A is insane for a spec that was originally designed for 0.5W/5V/100mA. I suspect this is the limit for USB charging as anything over 48V is considered a shock hazard by UL and 5A is already at the very top of the 3-5A limit of 20AWG for fire safety.
The advantage of USB-C is the power negotiation, so getting the higher rating only on circuits that actually support it should de doable and relatively safe.
The OnePlus cable melting give me the same impression as when hair power cables melt: it's a solved problem, the onus is on the maker.
Users needing the 240W have a whole chain of specialized devices, so buying a premium cable is also not much of an issue.
In modern(last 4 years approximately) GPUs, physical wiring distance is starting to contribute substantially to latency.
The problem you will encounter with pcie gen5 risers is signal integrity.
It's about 75-90% the speed of light, but even that's too slow.
Modern hardware components are getting to latencies in single digit nanoseconds. Light travels about 30cms in a nanosecond, so extending a pcie port to a different box is going to have a measurable difference.
Also, these were vital to systems like the MacPro Trashcan that had 0 PCIe slots. This system was a horrible system, and everyone I know that had one reverted back to their latest 2012 cheese grater systems with the chassis.
There was another guy I know that was building his own 3D render rig for his own home experimental use when those render engines started using GPUs. He built a 220v system that he'd unplug the dryer to use. It had way more GPU cards than he had slots for by using PCIe splitters. Again, these were not used to draw realtime graphics to a screen. They were solely compute nodes for the renderer. He was running circles around the CPU only render farm nodes.
People think that the PCIe lanes are the limiting factor, but again, that's just for getting the GPUs data back to the screen. As compute nodes, you do not need full lanes to get the benefits. But for doubting Thomas types like you, I'm sure my anecdotal isn't worth much
You might think you're joking, but there are gamer cases with space for two PSUs, and motherboards which can control a secondary PSU (turning both PSUs on and off together). When using a computer built like that, you have two main plugs, and the second PSU (thus the second mains plug) is usually dedicated to the graphics card(s).
The second one was turned on with a paperclip, obviously.
Turns out graphics cards and hard drives are completely fine with receiving power but no data link. They just sit there (sometimes with fans at max speed by default!) until the rest of the PC comes online.
This would still have the disadvantage that the PWROK (grey) cable from the second PSU would not be monitored by the motherboard, leaving the machine prone to partial reset quirks during brown-outs. Normally a motherboard will shut down when PWROK is deasserted, and refuse to come out of reset until it returns.
PSUs can be removed from the PDB and replaced and reconnected to a source of power without having to shut down the machine or even remove the case lid. You don't even need to slide the machine out of the rack if you can get to the rear.
Example:
https://www.fspgb.co.uk/_files/ugd/ea9ce5_d90a79af31f84cd59d...
Edit: For example, in a 3+1 redundant setting, 3 PSUs would be active and contributing toward 1/3 of the total load current each; 1 PSU would be in cold standby, ready to take over if 1 of the others fails or is taken offline.
https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQqLXew...
The problem isn't connectors, the problem (fundamentally) is to share electric connectivity between multiple conductors.
Sure, you can run 16A over 1.5 mm² wires, and 32A over 2.5 mm² (taken from [1], yes it's for 230V but that doesn't matter, the current is important not the voltage). And theoretically you could run 32A over 2x 1.5 mm² (you'd end up with 3 mm² cross section), but it's not allowed by code as when, for any reason, either of the two legs disconnects entirely or has increased resistance e.g. due to corrosion or a loose screw / wire nut (hence, please always use Wago style clamps - screws and wire nuts are not safe, even if torqued properly which most people don't), suddenly the other leg has to carry (much) more current than it's designed for and you risk anything from molten connectors to an outright fire. And that is what NVidia currently is running into, together with bad connections (e.g. due to dirt ingress).
The correct solution would be for the GPU to not tie together the incoming individual 12VHPWR pins on a single plane right at the connector input but to use MOSFETs and current/voltage sense to detect stuff like different current availability (at least it used to be the case with older GPUs that there were multiple ways to supply them with power and only, say, one of two connectors on the GPU being used) or overcurrents due to something going bad. But that adds complexity and, at least for the overcurrent protection, yet another microcontroller plus one ADC for each incoming power pin.
Alternatively each 12VHPWR pair could get its own (!) DC-DC converter down to 1V2 or whatever the GPU chip actually needs, but again that also needs a bunch of associated circuitry.
Another and even more annoying issue by the way is grounding - because all the electricity that comes in also wants to go back to the PSU and it can take any number of paths - the PCIe connector, the metal backplate, the 12VHPWR extra connector, via the shield of a DP cable that goes to a Thunderbolt adapter card's video input to that card, via the SLI connector to the other GPU and its ground...
Electricity is fun!
> Alternatively each 12VHPWR pair could get its own (!) DC-DC converter down to 1V2 or whatever the GPU chip actually needs, but again that also needs a bunch of associated circuitry.
So as you say, monitoring multiple inputs happened on the older xx90s, and most cards still do it. It's not hard.
Multiple DC-DC converters is something every GPU has. That's the only way to get enough current. So all you have to do is connect them to specific pins.
It still is because in the end you're dealing with dozens of amps on the "high" voltage side and hundreds of amps on the "low" (GPU chip) voltage side. The slightest fuck-up can and will have disastrous consequences.
GPUs these days are on the edge of physics when it comes to supplying them with power.
Doing the power conversion is hard.
Realizing that you already have several DC converters sharing the load, and deciding to power specific converters with specific pins, is comparatively easy. And the 3090 did it.
I'm not defending the shitty design here, but I'm all for always pushing the boundaries.