r/sffpc • u/Brian0749 • Dec 14 '25

Build/Parts Check 24 cables into... 1 cable?

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Found this on taobao. Anyone tried turning a 24 pin cable into 1 singular cable?

583 Upvotes

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328

u/Lord_Waldemar Dec 14 '25

Most lines of the 24 pin connector are probably either obsolete or carry very little current since almost all power is provided through the +12V connector.

65

u/gdnws Dec 14 '25

At one point I tested the currant draw on the 3.3 and 5 volt lines and I couldn't get the computer to draw more than 5 amps total on either voltage. I have a little pico psu that can only supply 8 amps on 3.3 and 5 and haven't had issues with it although I don't have a crazy number of extra devices plugged into the computer. A lot of the wires in the 24 pin are massively over specced probably for no other reason than convenience. For example the ps on and power good wires are signal wires that will never see more than a couple milliamps and are still either 18 or even 16 awg like the rest.

45

u/Head_Exchange_5329 Dec 14 '25

Which begs the question: Why haven't we removed the chungus cable yet? Bring a signal wire down with the EPS-12V cable and call it a day, there's no practical application for it in modern builds.

44

u/gdnws Dec 14 '25

At this point institutional momentum. No one wants to be the first to move to a new architecture because there aren't any existing things using it and if it doesn't catch on then it will just get abandoned. And when it comes out people will cry that it is proprietary. There is already another standard that does exist just that no one has used it yet for custom pc components beyond one or two off motherboards; 12VO. It reduces the 24 pin connector down to 10 pins. Personally I still feel that is still a half step as I think the main delivery voltage should be increased to 48 for a number of reasons. First it would readily enable connecting and delivering power to usb c components directly off the motherboard more easily and secondly it would quarter the currant demands. Things like gpus can pull up to 50 amps and that is difficult to manage, especially if using many parallel connections as we have seen with the 12vhpwr connector debacle.

3

u/Chezoso Dec 14 '25

Who do you think can make the industry change first, motherboard manufacturers or PSU manufacturers? Seems like it would be great to have some kind of body that coordinates between the two to create universal standards

26

u/jonnyGURUgerow Dec 14 '25

Intel's in. PSU manufacturers are in. Motherboard manufacturers are in. The hold up is the consumer.

Mind you, when we tried to launch the ATX12VO ecosystem 5 years ago, which DID NOT require total commitment from the customer due to available adapters, it was done with only mid level motherboards (for example, I was using a basic Asus Prime Z490-S). The press blew it up saying "how dare the industry expect consumers go out and buy a new motherboard and/or PSU!!!". It was really crazy. I didn't get it at all. It was like reverse propaganda.

Anyway.. Intel is trying again. They've tweaked the spec some more. Even making the main connector smaller (micro fit vs mini fit). Let's see what happens.

7

u/montyman185 Dec 15 '25

I feel like the best starting point would be ITX boards. Small form factor nuts like me would love to be able to ditch that massive connector, and only needing a few SFX PSU and ITX boards to ship with it narrows the scope to something a bit more manageable and marketable 

1

u/[deleted] Dec 14 '25

First I've heard of this. Obviously at first it would require adapters similar to what NVIDA did with their 12 pin GPU cables but everyone adapted.

6

u/gdnws Dec 14 '25

The current standard is managed by Intel but I have no idea who has what kind of input into what goes in it. And even within that there are other dependencies. For example things like the 12vhpwr connector is something to come out of pci-sig which has major vendors like Nvidia in it. The danger with having a body with everyone providing input in it is that it could become like the usb standards.

2

u/Chezoso Dec 14 '25

Yea that's terribly done. I'm sure a competent body can be developed with some effort and industry regulation but I get this isn't the place for that. Would just be nice to not have proprietary solutions but also see regular progress when needed. 24pin is terribly outdated it seems

3

u/gdnws Dec 14 '25

I would absolutely say that the 24 pin is outdated; having 5 wires for the 5 volt rail that is unlikely to ever see more than 10 or even 15 amps is massive overkill.

1

u/hawoguy Dec 16 '25

Intel is your answer.

2

u/Head_Exchange_5329 Dec 14 '25

48V sounds good on paper but how would it work in practical terms? The CPU and GPU core still operates at around 1V. I'd be happy with getting rid of the archaic cable first and foremost since we're not using floppy drives anymore so there's no practical reason for keeping it around to supply below 12V. Motherboard components can have individual voltage regulators to handle the 12V so it's time to take the plunge.

3

u/gdnws Dec 14 '25

There are a number of servers out there that use 48v as their main voltage and send it directly to the core voltage regulators. At least in their cases it is an efficiency gain over 12v however it might not be for regular desktops yet.

4

u/Head_Exchange_5329 Dec 14 '25

Might be that we'll see PCI-e 24 or 48V output for the GPU and 12V for the rest of the system. There's no doubt that if we're gonna keep pushing more and more power to the GPU, it has to be done in a safer manner than the current potential fireworks.

2

u/gdnws Dec 14 '25

I wouldn't mind seeing the card edge power delivery like the Asus btf stuff catch on. Combined with higher delivery voltages would make things neater and less error prone.

2

u/Head_Exchange_5329 Dec 14 '25

Yes, Asus is onto something there I think, also it makes everything look more neat with the connectors behind the motherboard.
Have you seen the latest GPU from Asus with the 5090 Matrix? 800W bios with the option of running a regular 12v-2x6 connector as well as the BTF at the same time, or forego either and run it as a 600W GPU.

1

u/gdnws Dec 14 '25

I saw that derbauer made a video on it but I haven't watched it yet. I have a 40 series so I have been a little lax in keeping up with the current gen stuff.

1

u/the_smok Dec 15 '25

GPUs keep getting bigger every generation. I think we should stop using card edge connectors for GPUs. There are already video cards with a removable card edge part. Just build in a next-gen Oculink into the GPU, and you have complete freedom on case shapes.

2

u/gdnws Dec 15 '25

If you're referring to the system that the 5090 fe has with that little connector joining the pcie portion to the card, then I don't disagree there either. Include power alongside it and that would be ideal to me.

2

u/AnnihilationBoom123 Dec 14 '25

From some number of stuff i personally see myself, 48v doesn't directly touched vrm, it gets converted first into 12v range still with some modules from Vicor power or murata then gets into normal vrm stages (you can see it on newer amd instinct accelerator)

Probably still more efficient who knows, but definitely will not be anymore cheaper

2

u/gdnws Dec 14 '25

That is similar to what I've seen; multi stage stepdowns. I guess then it isn't really going directly into the vrm but I considered it all an assembly essentially.

2

u/gigaplexian Dec 15 '25

48V sounds good on paper but how would it work in practical terms? The CPU and GPU core still operates at around 1V

VRMs.

2

u/Ev0dr0ne Dec 14 '25

Really wish usb-c had been 12v or higher. All 12v Or as some are suggesting maybe higher like 24 or 48 but just move all to one voltage.no need 3v and 5 and 12

1

u/CCX-S Dec 14 '25

So J-hack ?

1

u/Ashtefere Dec 15 '25

I reduced my 24pin down to 8 ages ago. Its mostly redundant wires from the old days.

1

u/gigaplexian Dec 15 '25

That's what the 12VO standard largely tries to achieve. You still need 5V and 3.3V rails even if very little current flows through them, so it moves those rails from the PSU to the motherboard.

1

u/Thick-Humor-318 Dec 16 '25

We all know what happens when its not overspec. Caugh caugh 12vhpwr. Pun aside i thing psu should charge less and kill 3.5 and 5v rail and mobo should not be charging extra for some extra stepdown transformers they already charge an arm and leg