What's taking so long? Corsair modular cable for RTX 12-pin

mnewxcv

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Corsair announced they would have a modular cable for the new RTX founders cards using the 12 pin connector, but I think the cable is harder to find than the GPUs themselves. What's going on here? I wouldn't think it would be too difficult for a PSU manufacturer to run some wire through a plastic connector. It's been 3 months since they announced it and I don't think the cable has been in stock once on their site. Even though it's $20 and it should be free..... they still can't seem to get it in stock.

https://www.corsair.com/us/en/Categ...-Supplies/12-pin-GPU-Power-Cable/p/CP-8920274
 

GiGaBiTe

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Corsair has had supply chain issues like everyone else, getting anything from them for the past year has been a challenge. But expecting them to give away free adapters to a product they had no control over that was released after their products is a bit rude. The FE cards are also supposed to come with this adapter cable in box, there should be no reason to need one unless the card was gotten off the back of a truck in some dark alley.

Even assuming a legitimate need for the connector, it's really not terribly difficult to make one of these adapters. The 12 pin Molex Micro-Fit 3.0 connector is readily available from several places, so is the 8 pin Minifit Jr. connector, and you can get wire anywhere. The crimp tool is also not that expensive, you can get them for $15 on Ebay.

Heck, I could probably make and sell these.
 

mnewxcv

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Corsair has had supply chain issues like everyone else, getting anything from them for the past year has been a challenge. But expecting them to give away free adapters to a product they had no control over that was released after their products is a bit rude. The FE cards are also supposed to come with this adapter cable in box, there should be no reason to need one unless the card was gotten off the back of a truck in some dark alley.

Even assuming a legitimate need for the connector, it's really not terribly difficult to make one of these adapters. The 12 pin Molex Micro-Fit 3.0 connector is readily available from several places, so is the 8 pin Minifit Jr. connector, and you can get wire anywhere. The crimp tool is also not that expensive, you can get them for $15 on Ebay.

Heck, I could probably make and sell these.
Fair enough. As for them being free, I more or less meant their new PSUs should ship with them, not necessarily that they should make these cables and mail them to you for no charge, though I think seasonic promised free cables. FE cards have a cable which is about 4" long, making it difficult to cable manage, that's all. I will look into the crimp tool, I never got around to repinning or sleeving cables in my years as a PC enthusiast.

I know some third parties will make cables if you give them the model of your PSU, but not entirely sure I trust a random company not to pin it wrong, or use cheap wire, etc. Thanks for the feedback though, looking into DIY now.
 

Zepher

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Fair enough. As for them being free, I more or less meant their new PSUs should ship with them, not necessarily that they should make these cables and mail them to you for no charge, though I think seasonic promised free cables. FE cards have a cable which is about 4" long, making it difficult to cable manage, that's all. I will look into the crimp tool, I never got around to repinning or sleeving cables in my years as a PC enthusiast.

I know some third parties will make cables if you give them the model of your PSU, but not entirely sure I trust a random company not to pin it wrong, or use cheap wire, etc. Thanks for the feedback though, looking into DIY now.
Since only the Nvidia branded one uses that connector, it shouldn't be included with every PSU as that is a cost that is added to every purchaser. Most people won't be using the cable.
 

mnewxcv

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Since only the Nvidia branded one uses that connector, it shouldn't be included with every PSU as that is a cost that is added to every purchaser. Most people won't be using the cable.
a good point. Back in september I think some makers (seasonic? Evga?) said new PSUs will ship with the cable, but back then it seemed like maybe there would be wider adoption of the standard. If it is limited to FE cards and doesn't gain traction with AIBs, it would be a waste of time to include the cable with EVERY psu. I hope it does become popular though, if it does indeed spec 850w, since a single connector is a lot cleaner looking than 3 8-pin pcie power cables.
 

GiGaBiTe

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I know some third parties will make cables if you give them the model of your PSU, but not entirely sure I trust a random company not to pin it wrong, or use cheap wire, etc. Thanks for the feedback though, looking into DIY now.

Here's a BOM of the parts required to make one cable. The only thing I'm questioning is the 8 pin socket. Molex doesn't have a part number for the female socket for the 8 pin PCIe power connector for a crimp style, only a wire-to-board type. It looks to be correct from looking at PCIe adapter cables.

12 Pin Micro-Fit 3.0 Connector:
1 x https://www.mouser.com/ProductDetail/538-43025-1200
12 x https://www.mouser.com/ProductDetail/538-43030-0038

8 Pin PCIe Power Socket
2 x https://www.mouser.com/ProductDetail/538-46993-0810
16 x https://www.mouser.com/ProductDetail/538-39-00-0041

Here's the crimper, wire and optional cable sleeving and heat shrink. YMMV on Ebay wire, but Mouser wants too much money for small sections of wire. Auto parts stores sell wire in pre-cut lengths and sometimes off the roll. Home Depot and Lowes also have wire, but I don't know if they have long runs of stranded wire.

Crimper:
https://www.ebay.com/itm/113722821534

100' Roll Yellow 18 AWG Wire:
https://www.ebay.com/itm/174515430319

100' Roll Black 18 AWG Wire:
https://www.ebay.com/itm/193414320953

(optional cable sleeving)
https://www.ebay.com/itm/222303786890

(optional heat shrink)
https://www.ebay.com/itm/222710969639

Here's the pinout of the connector:
xysaJrZzfgv5OxWK.jpg

If in doubt, you can use a multimeter on your existing smaller one.
 

mnewxcv

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Here's a BOM of the parts required to make one cable. The only thing I'm questioning is the 8 pin socket. Molex doesn't have a part number for the female socket for the 8 pin PCIe power connector for a crimp style, only a wire-to-board type. It looks to be correct from looking at PCIe adapter cables.

12 Pin Micro-Fit 3.0 Connector:
1 x https://www.mouser.com/ProductDetail/538-43025-1200
12 x https://www.mouser.com/ProductDetail/538-43030-0038

8 Pin PCIe Power Socket
2 x https://www.mouser.com/ProductDetail/538-46993-0810
16 x https://www.mouser.com/ProductDetail/538-39-00-0041

Here's the crimper, wire and optional cable sleeving and heat shrink. YMMV on Ebay wire, but Mouser wants too much money for small sections of wire. Auto parts stores sell wire in pre-cut lengths and sometimes off the roll. Home Depot and Lowes also have wire, but I don't know if they have long runs of stranded wire.

Crimper:
https://www.ebay.com/itm/113722821534

100' Roll Yellow 18 AWG Wire:
https://www.ebay.com/itm/174515430319

100' Roll Black 18 AWG Wire:
https://www.ebay.com/itm/193414320953

(optional cable sleeving)
https://www.ebay.com/itm/222303786890

(optional heat shrink)
https://www.ebay.com/itm/222710969639

Here's the pinout of the connector:
View attachment 306200

If in doubt, you can use a multimeter on your existing smaller one.
any idea if the PSU side of the PSU cable on the SF750 is available as a connector, so that it would be a single cable instead of an extension?

a73d4c38-d8c0-4f99-b86a-a2ed32f984d3.jpg
 

[Spectre]

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Here's a BOM of the parts required to make one cable. The only thing I'm questioning is the 8 pin socket. Molex doesn't have a part number for the female socket for the 8 pin PCIe power connector for a crimp style, only a wire-to-board type. It looks to be correct from looking at PCIe adapter cables.

12 Pin Micro-Fit 3.0 Connector:
1 x https://www.mouser.com/ProductDetail/538-43025-1200
12 x https://www.mouser.com/ProductDetail/538-43030-0038

8 Pin PCIe Power Socket
2 x https://www.mouser.com/ProductDetail/538-46993-0810
16 x https://www.mouser.com/ProductDetail/538-39-00-0041

Here's the crimper, wire and optional cable sleeving and heat shrink. YMMV on Ebay wire, but Mouser wants too much money for small sections of wire. Auto parts stores sell wire in pre-cut lengths and sometimes off the roll. Home Depot and Lowes also have wire, but I don't know if they have long runs of stranded wire.

Crimper:
https://www.ebay.com/itm/113722821534

100' Roll Yellow 18 AWG Wire:
https://www.ebay.com/itm/174515430319

100' Roll Black 18 AWG Wire:
https://www.ebay.com/itm/193414320953

(optional cable sleeving)
https://www.ebay.com/itm/222303786890

(optional heat shrink)
https://www.ebay.com/itm/222710969639

Here's the pinout of the connector:
View attachment 306200

If in doubt, you can use a multimeter on your existing smaller one.

You can sort of skip the crimper if you already have a wire stripper or even good hands and pliers.
 

GiGaBiTe

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Falkentyne

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I thought that this was the pin-out of the connector, guys?
And I would suggest 16 AWG wires, not 18 AWG. Seasonic uses 16 AWG for their FE cable.

FE_Pinout.png


Edited because I don't know the difference between aug and awg, apparently.
 
Last edited:

MaxHughes

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Corsair announced they would have a modular cable for the new RTX founders cards using the 12 pin connector, but I think the cable is harder to find than the GPUs themselves. What's going on here? I wouldn't think it would be too difficult for a PSU manufacturer to run some wire through a plastic connector. It's been 3 months since they announced it and I don't think the cable has been in stock once on their site. Even though it's $20 and it should be free..... they still can't seem to get it in stock.

https://www.corsair.com/us/en/Categories/Products/Accessories-|-Parts/PC-Components/Power-Supplies/12-pin-GPU-Power-Cable/p/CP-8920274
Why would Corsair retool for something we can't buy?
 

MaxHughes

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Here's a BOM of the parts required to make one cable. The only thing I'm questioning is the 8 pin socket. Molex doesn't have a part number for the female socket for the 8 pin PCIe power connector for a crimp style, only a wire-to-board type. It looks to be correct from looking at PCIe adapter cables.

12 Pin Micro-Fit 3.0 Connector:
1 x https://www.mouser.com/ProductDetail/538-43025-1200
12 x https://www.mouser.com/ProductDetail/538-43030-0038

8 Pin PCIe Power Socket
2 x https://www.mouser.com/ProductDetail/538-46993-0810
16 x https://www.mouser.com/ProductDetail/538-39-00-0041

Here's the crimper, wire and optional cable sleeving and heat shrink. YMMV on Ebay wire, but Mouser wants too much money for small sections of wire. Auto parts stores sell wire in pre-cut lengths and sometimes off the roll. Home Depot and Lowes also have wire, but I don't know if they have long runs of stranded wire.

Crimper:
https://www.ebay.com/itm/113722821534

100' Roll Yellow 18 AWG Wire:
https://www.ebay.com/itm/174515430319

100' Roll Black 18 AWG Wire:
https://www.ebay.com/itm/193414320953

(optional cable sleeving)
https://www.ebay.com/itm/222303786890

(optional heat shrink)
https://www.ebay.com/itm/222710969639

Here's the pinout of the connector:
View attachment 306200

If in doubt, you can use a multimeter on your existing smaller one.
Thanks Dude, that nice. Crystal clear. To bad they didn't just make a card with two six pin connectors. I've got those.
 

GiGaBiTe

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Thanks Dude, that nice. Crystal clear. To bad they didn't just make a card with two six pin connectors. I've got those.

The RTX 3090/3080 pull far too much power for two 6 pin PCIe connectors. You'd at minimum need two 8 pin, and more realistically need three or four 8 pin connectors. There are reports of the 3090 pulling up to 550W when overclocked under peak demand.
 

[Spectre]

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The RTX 3090/3080 pull far too much power for two 6 pin PCIe connectors. You'd at minimum need two 8 pin, and more realistically need three or four 8 pin connectors. There are reports of the 3090 pulling up to 550W when overclocked under peak demand.

The 8 pin's extra two pins do not contribute to its capacity (physically they are the same). Each pin in the six that carries 12v can support 9A. So, you could pull 54A across two six pin PCIe connectors.
 

GiGaBiTe

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The 8 pin's extra two pins do not contribute to its capacity (physically they are the same). Each pin in the six that carries 12v can support 9A. So, you could pull 54A across two six pin PCIe connectors.

8 pin PCIe connectors can deliver more power, at least if the PCIe spec is followed a certain way. Pin 2 on the 6 pin PCIe connector is listed as optional, so you can have 6 pin connectors with only two 12v power pins. Most PSU manufacturers usually have pin 2 connected, but I have seen a handful where it was not connected (usually on OEM systems), or jumpered via a short wire to an adjacent 12v pin (usually on crappy PSUs or AMP to PCIe adapters), making the total available power lower.
 

[Spectre]

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8 pin PCIe connectors can deliver more power, at least if the PCIe spec is followed a certain way. Pin 2 on the 6 pin PCIe connector is listed as optional, so you can have 6 pin connectors with only two 12v power pins. Most PSU manufacturers usually have pin 2 connected, but I have seen a handful where it was not connected (usually on OEM systems), or jumpered via a short wire to an adjacent 12v pin (usually on crappy PSUs or AMP to PCIe adapters), making the total available power lower.

There are 3 12v and 3 ground on 6 pin PCIe connectors. 8 pin only add two more grounds in most cases since people split them from other grounds (but should be sense). Each pin is capable of 9A. So both a six pin and an eight pin PCIe connector has the same physical capacity of 27A per connector. I have tested it many many times over the 14 years I have been reviewing power supplies.
 

mnewxcv

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There are 3 12v and 3 ground on 6 pin PCIe connectors. 8 pin only add two more grounds in most cases since people split them from other grounds (but should be sense). Each pin is capable of 9A. So both a six pin and an eight pin PCIe connector has the same physical capacity of 27A per connector. I have tested it many many times over the 14 years I have been reviewing power supplies.
is there a different spec for awg between 6 and 8?
 

GiGaBiTe

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There are 3 12v and 3 ground on 6 pin PCIe connectors.

No. There are two 12v wires, with a third (pin 2) being optional. Most manufacturers include the third wire, but it is not always the case.

https://allpinouts.org/pinouts/connectors/power_supply/pci-express-pcie-6pin-power/

Which can lead to subpar things like these:

https://c.76.my/Malaysia/4-pin-mole...-atx-cp-c-108-yongmf83-1502-26-yongmf83@5.jpg
https://h30434.www3.hp.com/t5/image/serverpage/image-id/139875iAB2678A24A784170?v=1.0

The last two pictures are OEM systems, which is what I said earlier. You cannot always assume that a 6 pin PCIe connector will have three 12v wires. That drops the current rating of the connector by 33%.

It's not a fringe case to have such configurations, I've seen it quite a bit in OEM systems and crappy power supplies.
 

[Spectre]

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No. There are two 12v wires, with a third (pin 2) being optional. Most manufacturers include the third wire, but it is not always the case.

https://allpinouts.org/pinouts/connectors/power_supply/pci-express-pcie-6pin-power/

Which can lead to subpar things like these:

https://c.76.my/Malaysia/4-pin-mole...-atx-cp-c-108-yongmf83-1502-26-yongmf83@5.jpg
https://h30434.www3.hp.com/t5/image/serverpage/image-id/139875iAB2678A24A784170?v=1.0

The last two pictures are OEM systems, which is what I said earlier. You cannot always assume that a 6 pin PCIe connector will have three 12v wires. That drops the current rating of the connector by 33%.

It's not a fringe case to have such configurations, I've seen it quite a bit in OEM systems and crappy power supplies.

Sigh, it is not like I do this as a job or anything. And here is how you know what you are saying doesn't make sense. "That drops the current rating of the connector by 33%." yet the number given on teh spec sheet is 75W versus 150W. That isn't 33%. You want to know why? Because the 6 pin and 8 pin connectors as implemented are the same. In fact, in most cases the exact same as the extra 2 ground wires are split off of two existing instead of putting in the sense runs that are supposed to be there. 9A per 12v pin. Three 12v pins per connector. 27A per connector is actual capacity. I have taken apart more power supplies and had more than you would ever guess. OEM's doing their own thing (like all kinds of fun all 12v system boards and such) is not the point (still with two pins you would get 216W not 150W or 75W of capacity). The point is the 6 pin PCIe connector is electrically the same as the 8 pin PCIe connector.
 

GiGaBiTe

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Sigh, it is not like I do this as a job or anything. And here is how you know what you are saying doesn't make sense.

You're basically saying the official spec and pictures of examples of said spec are wrong. You seem to have a problem with the spec and real world examples of the spec.

"That drops the current rating of the connector by 33%." yet the number given on teh spec sheet is 75W versus 150W. That isn't 33%.

Removing one wire from 3 power wires drops the current rating of the connector 33%. Assuming your quoted figure of 9 amps, you drop from 27 amps to 18 amps by removing one wire. Your 9 amp figure is also not technically correct, current rating is based on wire length. Too long of a wire run and wire resistance will become a problem, which is why you de-rate the current the longer a wire run is.

You're the one that brought up the 75/150W official ratings, which I was never talking about to begin with. I was talking about the absolute ratings of the connector and the wire.

I have taken apart more power supplies and had more than you would ever guess.

I've been working with electrical equipment for 20 years, including complex power supply repair. Please stop playing the holier than thou card, it's rude and uncalled for.

OEM's doing their own thing (like all kinds of fun all 12v system boards and such) is not the point.

Except it is the point, and what I was trying to say over the last several posts. OEMS are not doing whatever they want, it's part of the official spec. Pin 2 is optional on a 6 pin connector, which is a 12v power wire, not a random ground. Removing one power wire drops the load carrying capability of the connector 33%, irregardless of the "allowable" 75 or 150 watts. I'm not sure how much simpler I can make this.
 

[Spectre]

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You're basically saying the official spec and pictures of examples of said spec are wrong. You seem to have a problem with the spec and real world examples of the spec.



Removing one wire from 3 power wires drops the current rating of the connector 33%. Assuming your quoted figure of 9 amps, you drop from 27 amps to 18 amps by removing one wire. Your 9 amp figure is also not technically correct, current rating is based on wire length. Too long of a wire run and wire resistance will become a problem, which is why you de-rate the current the longer a wire run is.

You're the one that brought up the 75/150W official ratings, which I was never talking about to begin with. I was talking about the absolute ratings of the connector and the wire.



I've been working with electrical equipment for 20 years, including complex power supply repair. Please stop playing the holier than thou card, it's rude and uncalled for.



Except it is the point, and what I was trying to say over the last several posts. OEMS are not doing whatever they want, it's part of the official spec. Pin 2 is optional on a 6 pin connector, which is a 12v power wire, not a random ground. Removing one power wire drops the load carrying capability of the connector 33%, irregardless of the "allowable" 75 or 150 watts. I'm not sure how much simpler I can make this.

No, I have a problem with cherry picked examples of things that are not representative of the actual implementation of the specification.

No, current rating is not based on wire length in the way you want to make it. I have literally done this testing and published it. The lengths at which PSU cables operate the limitation is the pin and the crimp quality, not the wire length.

I was always talking about what the connector will actually do. You were the one saying that "The RTX 3090/3080 pull far too much power for two 6 pin PCIe connectors. You'd at minimum need two 8 pin" which is demonstrably false as the 6 pin connector can deliver as much as the 8 pin connector (or if you want to get your example even a nonimplemented 2 pin 6 pin connector could do what you say can't be done since two of those bastard 6 pin connectors can give you 432W and the slot will give you 75W for a total of .........507W because with OC numbers no one is actually measuring the DC power through the PCIe connectors and the slot they are measuring AC power changes). I have done it in review after review after review. There is literally no difference. Show me your actual work, not hypothetical. The physical work.

And, you know it.......from post 1044836394
407842_xysaJrZzfgv5OxWK.jpg

https://hardforum.com/threads/whats...cable-for-rtx-12-pin.2004605/#post-1044836394
Which......who is author of?

Great, I'm glad you have 20 years in electrical equipment repair that doesn't mean I would let you near an ATX12v/EPS power supply anymore than I would start working on 480v 3 phase because I have years reviewing and training on low voltage. Literally doesn't matter, it is not transferable. We can start a big credentials war if you want, but it won't go well for you. I mentioned it because you are talking about hypotheticals without experience in this matter. I speak from not hypotheticals.

You can bang on about whatever you would like. However, in the implementation of the PCIe specification for everything but people who don't follow the implementation the 6 pin connector is no different in how much power it can provide than the 8 pin connector. Full stop.
 

GiGaBiTe

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No, I have a problem with cherry picked examples of things that are not representative of the actual implementation of the specification.

No, the problem you have is that you refuse to accept physical evidence of valid implementations of the standard. A random google search for "PCIe 6 pin one wire missing" is not cherry picking. One of those images being in a mass manufactured OEM system definitely precludes it.

No, current rating is not based on wire length in the way you want to make it. I have literally done this testing and published it. The lengths at which PSU cables operate the limitation is the pin and the crimp quality, not the wire length.

Current rating of a wire is based on wire length. FULL STOP. The straw man argument you added is irrelevant. If you have a problem with how wire load ratings are calculated, call up the IEC and complain to them.


The image is one of the first results on google image search, it was never guaranteed to be completely accurate, just accurate enough to make a functional adapter. If you want an errata, here you go.

Spsgx.png
https://allpinouts.org/pinouts/connectors/power_supply/pci-express-pcie-6pin-power/

If you want it from the horses' mouth, you're free to go to the PCISIG website and look it up yourself.

Great, I'm glad you have 20 years in electrical equipment repair that doesn't mean I would let you near an ATX12v/EPS power supply anymore than I would start working on 480v 3 phase because I have years reviewing and training on low voltage. Literally doesn't matter, it is not transferable. We can start a big credentials war if you want, but it won't go well for you. I mentioned it because you are talking about hypotheticals without experience in this matter. I speak from not hypotheticals.

Really a shame that all you can do is rely on straw man attacks, assumptions and burying your head in the sand. I'm not going to get into a credential war with you because frankly, your credentials are worthless to me based on your behavior alone. I'd never trust you as a reviewer since you ignore standards and move the goalpost around to fit your narrative. You also seem to like filling in the blanks about other people to make yourself look validated. I never told you which electrical equipment and power supplies I worked on, you made that part up entirely on your own.

You can bang on about whatever you would like. However, in the implementation of the PCIe specification for everything but people who don't follow the implementation the 6 pin connector is no different in how much power it can provide than the 8 pin connector. Full stop.

You can keep painting over your screen to hide facts you don't want to see, doesn't make them magically not exist.
 

MaxHughes

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The RTX 3090/3080 pull far too much power for two 6 pin PCIe connectors. You'd at minimum need two 8 pin, and more realistically need three or four 8 pin connectors. There are reports of the 3090 pulling up to 550W when overclocked under peak demand.
One 12 pin or two six pin both have 6 negative and 6 positive conductors. Did you even look at the diagram?
 

Meeho

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Though a bit heated, I like the discussion above. What I'm wondering is, since the 6-pin allows for three 12 V wires, why was the 8-pin created?
 

Format _C:

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Why so many different connector types, What do the "sense" wires do?
I have a few "extra" power supplies laying around why is the PCI-e 8 pin even different the the ATX/EPS 8 pin that makes it more complicated then the multiple different types of connectors all with different "keying"
 

Format _C:

2[H]4U
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Oh all of this reminds me of the "early" days of front panel USB/Audio with 10 individual pins for USB and another set for audio who remembers "Front-X" the bay adapters for front panels.
Make one PCIe GPU power connector that will work on the most power hogging modern card and if a maker uses a non-standard pin-out they will have to include an adapter.
 

GiGaBiTe

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Though a bit heated, I like the discussion above. What I'm wondering is, since the 6-pin allows for three 12 V wires, why was the 8-pin created?

While the 6 pin connector allows for three 12v conductors, the 8 pin power connector mandates three 12v conductors. Though as with the 6 pin, manufacturers still don't always make 8 pin cables to spec.

Why so many different connector types, What do the "sense" wires do?

The sense wires are used to detect voltage drop across the cable. Any length of wire is going to have some voltage drop, which increases the more current that the wire carries. The sense wires only have a tiny amount of current on them, so are able to better detect the drop in voltage on the device end of the cable. The power supply uses them to better regulate the current output so the powered device doesn't starve for power.
 

Tsumi

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Why so many different connector types, What do the "sense" wires do?
I have a few "extra" power supplies laying around why is the PCI-e 8 pin even different the the ATX/EPS 8 pin that makes it more complicated then the multiple different types of connectors all with different "keying"

It's the classic "I'm going to make a standard that is better than all the other standards" leading to a mess of competing standards.

The sense wire tells the GPU how much power it can pull from the connector.

While the 6 pin connector allows for three 12v conductors, the 8 pin power connector mandates three 12v conductors. Though as with the 6 pin, manufacturers still don't always make 8 pin cables to spec.



The sense wires are used to detect voltage drop across the cable. Any length of wire is going to have some voltage drop, which increases the more current that the wire carries. The sense wires only have a tiny amount of current on them, so are able to better detect the drop in voltage on the device end of the cable. The power supply uses them to better regulate the current output so the powered device doesn't starve for power.

Once again, as you have been multiple times through this thread, you are flat out wrong. The sense wires as implemented on the PCI-E spec are to tell the GPU how much power it is allowed to draw through the connector. If sense B is not connected, the GPU, assuming it follows proper PCI-E implementation, will default into a low power mode. If sense A and B are not connected, it will treat the PCI-E power connection as unplugged and operate at an even lower power mode. It has absolutely nothing to do with voltage sensing as that is entirely PSU side with the implementation of extra wiring, not connectors.

Also, you seem to have a real problem differentiating the hypothetical from the real world. No one buying an RTX 3080 will be getting a $15 bottom barrel PSU.
 

GiGaBiTe

[H]ard|Gawd
Joined
Apr 26, 2013
Messages
1,437
Once again, as you have been multiple times through this thread, you are flat out wrong.

Once again, if you have a problem with the PCIe spec as defined by the PCISIG group, you need to take up your problems with them. You can stop your nonsense driveby crap, thanks.

The sense wires as implemented on the PCI-E spec are to tell the GPU how much power it is allowed to draw through the connector. If sense B is not connected, the GPU, assuming it follows proper PCI-E implementation, will default into a low power mode. If sense A and B are not connected, it will treat the PCI-E power connection as unplugged and operate at an even lower power mode. It has absolutely nothing to do with voltage sensing as that is entirely PSU side with the implementation of extra wiring, not connectors.

I re-looked up this and it appears to be the case. This is the only thing I've been incorrect on, everything else is you having a problem with a standards group.

Also, you seem to have a real problem differentiating the hypothetical from the real world. No one buying an RTX 3080 will be getting a $15 bottom barrel PSU.

Can't tell if trolling or you're just that oblivious. I'm guessing you also have next to no experience doing real world tech support on DIY machines the public at large builds.

Literally every tech support site to ever exist on the internet in the past, present and future called you and said you have no idea what you're talking about if you think such a scenario you describe not being possible. There are even people in our own power supply subforum who have asked for advice on using grossly inadequate and/or dangerous PSUs on high demand CPUs and GPUs. I've not seen an RTX on a Logisys equivalent yet, but it will happen eventually, just as it has happened for decades past for every prior hardware generation.
 

BinarySynapse

[H]F Junkie
Joined
Feb 6, 2006
Messages
15,068
Oh all of this reminds me of the "early" days of front panel USB/Audio with 10 individual pins for USB and another set for audio who remembers "Front-X" the bay adapters for front panels.
Make one PCIe GPU power connector that will work on the most power hogging modern card and if a maker uses a non-standard pin-out they will have to include an adapter.


What you’re seeing is the evolution of a standard. PCIe (originally called 3GIO) design started in the late 90’s. At that time, it just wasn’t conceivable that anything plugged into an expansion slot would ever need more than 150w of power. Even graphics cards of the day were at most 50w. So 75w from the slot and an additional 75w (across two +12v pins) from an auxiliary connector was thought to be more than enough power for the anticipated lifespan of PCIe (which was only a few years).


When PCIe didn’t get replaced, and GPU power draw blew up, it became apparent that 150w wasn’t enough. So the revised PCIe spec (2.0) moved to make the third +12v pin mandatory. But since the original spec only called for two +12v, it was possible to plug new spec board into a system with an old spec PSU using an “underpowered” connector. The boards needed know it had three +12v available, so a second sense pin was added... which means a new connector. A second 6-pin was allowed for 300w total board power,


Fifteen years later, Nvidia is saying 300w isn’t enough anymore and is proposing a new standard.
 
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