# PCIE 8 pin header part number?

#### lmbrown3900

##### New Member
Hi all,

I'm building a bench power supply using a computer SMPS. I'd like to use the PCI-E 8 pin cables to provide more current to the output. I've spent the better part of an entire day trying to locate the manufacturer(s) of them.

Computer power supplies have the "plug", and video cards have the mating "connector / header / receptacle" that I'm looking for. I have the 8 pin EPS12V and 24 pin main PCB connectors located. The polarization and pinout of the PCIE 8 pin connector is different than the EPS12V though.

Does anyone know who makes the 8 pin PCIE power connector?

#### theg

##### New Member
Did you find the header part number???

I am looking for one myself.

Thanks.

#### lmbrown3900

##### New Member
Hi theg

No luck. Wound up using 6 pin versions with 8 pin to 6 pin connecting cables . More current per wire than I wanted, but still workable.

#### theg

##### New Member

I will update you if I find somthing

#### cr0sh

##### Member
Ok - I think I found what you are looking for. It is called a "Molex Mini-Fit Jr" connector; you can find more detail at Molex's site:

Molex | Connectors, Interconnects and Cable Assemblies

You are going to want the "8 circuit" variety, I believe for 8 pins (they come in different sizes). You can probably contact Molex directly, and they can help you, so that you can make sure of what you are getting; likely you would need to go thru a place like Digikey or Mouser (RS, Farnell, etc - whatever it is in your part of the world) to actually order the parts.

#### lmbrown3900

##### New Member
Hi cr0sh,

I went through the apps folks at Molex, Tyco, FCI, Samtec, Berg and others. No luck. I checked the ATX spec - no luck. I contacted 2 of the high end SMPS manufacturers who have products on the market: Quote "That information is not available to us."

Now, I don't know if there is a specific "trade group" for harmonizing the power connections for video cards to ATX power supplies (that's what the connector is FOR, correct?) but it would be even more reassuring to me to think that SOMEONE in the industry had a clue...

Really, I mean, think about it...where else can you get a 450W multiple output, regulatory approved, power supply for under 20 bucks? Seems like more products would be designed using them as a power source if the documentation was clear.

#### cr0sh

##### Member
From what I could find in my research, the 8-pin connector is a Molex Mini-Fit Jr":

Molex - Mini-Fit Jr.

They come in single row or dual-row, 2 to 24 circuit; you want dual row, 8 circuit, I am pretty certain. For instance, here is the receptacle (part #0039012080):

Molex Connector Part Number - 0039012080

You probably have to buy pins for it separately (and maybe even a pin installer tool; I'm not certain) - Molex sells those, too.

Here is the header, what the receptacle plugs into (part #0039281083):

Molex Connector Part Number - 0039281083

Molex has a sampling process, maybe you can use that to try it out - if it isn't right, you probably haven't lost much, if anything.

#### theg

##### New Member
Thanks cr0sh,

Never the less, the EPS12V is not the same spec as the PCIe Power (different pin shapes, a plastic bridge and different pin locations.)

For example, Molex is manufacturing this: Molex Connector Part Number - 0457180002
which is a 3x2 standard PCIe power pcb header, but they do not have (I talked to Molex) the 4x2.

I heard that nVidia manufactures these connectors by themselves...

##### Well-Known Member
I have always found this particular site useful. If you muddle through it you will find just about all the part numbers used for the assorted connectors etc. Pretty useful stuff and pictures.

I like pictures.

Ron

#### lmbrown3900

##### New Member
Check the polarization per the datasheet

Hi cr0sh, Hi Ron,

I agree the harness connector seems to be a Molex Mini-Fit Jr series component. I've also used the playtool site for reference a number of times. If you look at the datasheets referenced, you'll see the polarization between cable connector and header are different. The 8 pin header shown on pages 1 & 3 of the Molex 39-28-1083 datasheet is used for the 8 pin EPS+12V supply header. The PCIE-8 header is nowhere to be found.

I've spoken with tech support at Ultra and Corsair, who sell modular SMPSs for computers, and who's products USE these headers. Depending on who I spoke with there is either: no information available, it's a custom part, it's a trade secret - whatever. For something that should be an industry standard, why is this part so obscure?

#### cr0sh

##### Member
Hi cr0sh, Hi Ron,

I agree the harness connector seems to be a Molex Mini-Fit Jr series component. I've also used the playtool site for reference a number of times. If you look at the datasheets referenced, you'll see the polarization between cable connector and header are different. The 8 pin header shown on pages 1 & 3 of the Molex 39-28-1083 datasheet is used for the 8 pin EPS+12V supply header. The PCIE-8 header is nowhere to be found.
I see what you're saying, now. I did some more research on the molex site, and comparing with what is on the playtool site; the closest I could find with that info was the Molex Micro-Fit, 3.0 series:

Molex - Micro-Fit, 3.0

Specifically this part (#0430250800):

Molex Connector Part Number - 0430250800

But even that doesn't match up exactly. I don't have one of these power supplies or connectors in-hand; I am going on "what I can see" - which isn't much without measurements and other details. It also doesn't help that Molex doesn't show actual pictures, only drawings, and even there shows drawings for certain connectors in place of the one you are looking at (WTH?). I can see why you are frustrated.

I've spoken with tech support at Ultra and Corsair, who sell modular SMPSs for computers, and who's products USE these headers. Depending on who I spoke with there is either: no information available, it's a custom part, it's a trade secret - whatever. For something that should be an industry standard, why is this part so obscure?
Who you would need to speak with would be a "product engineer", not a tech support individual. However, these people (regardless of industry or company) are like "golden eggs"; difficult to contact unless you personally know them. Even if you manage to find an email address or other contact (say via linked-in or some other similar site), they will probably clam up on information like this. I know what you mean though about "industry standards" being obscure. They're only obscure, though, because technically, you're not in the industry. Something I have found, though, is that for every industry, there are trade journals and organizations; the PC power supply industry is probably no different. You might see if you can worm your way into their secrets through that route. There's also the possibility of social engineering your way past tech support...

I'm not sure what else to tell you - this is a strange problem.

#### cr0sh

##### Member
Heh - found this:

PCI Specifications Documents
Index of /~dft0802/specs

I can't say I disagree with him - these kinds of shenanigans really tick me off; they ultimately say to me "you aren't allowed to have full control of the device you bought", which is rapidly coming to be everything.

I guess now you know why nobody is saying anything - I would be willing to bet that in addition to the $3000.00 you have to pay for "membership" in the PCI-SIG, you also have to agree to not share any info you gain from the membership (which would include the specs and part numbers for the power connectors, most likely). #### lmbrown3900 ##### New Member Letter to PCI-SIG Hi cr0sh, FYI, I just sent this to the email address provided on the PCI-SIG website - though I doubt it'll accomplish anything... ---------------------------------------------------------------------------------- Hello, My request is simple - I need the MFR and part number of the PCB connector used for the PCI-E 8 pin power cable connector. That’s it. What is the point in not allowing access to basic interface component information? Every other connector on the supply is specified – why not this one? Modular computer power supplies are readily available, dependable and inexpensive; and you control ONE of the interface components. Wouldn’t it make sense to provide the connector information so the SMPS can be used for devices OTHER THAN a PCI video card? LMBrown #### cr0sh ##### Member Hi cr0sh, FYI, I just sent this to the email address provided on the PCI-SIG website - though I doubt it'll accomplish anything... Well - I am not sure you will get a reply or anything regarding that email, either; I decided to write my own email to their "General/Administration" contact - here is what I wrote: To whom it may concern: I am attempting to find information regarding the manufacturer and part number for the 8-pin PCI-E power connector found on newer ATX power supplies for supplying extra power to PCI-E graphics cards. I am hobbyist who intends to use this information in order to purchase these connectors for my own independent, personal projects. I cannot afford to sign up for membership at this time (it is well beyond my budget to do so - besides, have you ever spent$3000.00 just to find out information about a likely 25 cent part?). Please advise - thank you!

If I get anything back, I will share it here...

#### lmbrown3900

##### New Member
A response!

Hi cr0sh,

Just received this. Haven't had a chance to check it out yet, but figured I'd post it as a FYI...

Thank you for your message. PCI-SIG does not sell graphics cards or any other consumer products. Therefore, we don’t have information regarding the manufacturer of specific parts used in graphics and video cards. However, there is a vendor, Rosenberger of North America (Welcome to Rosenberger of North America, LLC - Manufacturer of high-frequency coaxial connectors, automotive connectors, RF test & measurement products and cable assemblies) who sells connectors for PCIe Compliance Test Fixtures who may sell the PCB connectors or can provide you with the name of other vendors who sell these parts.

#### cr0sh

##### Member
That was the same message I got when I just now checked my email; I sent an email to them asking for information about the connector - if I hear anything, I will post back here!

#### cr0sh

##### Member
Well, I got a small response from Rosenberger; they seem confused:

Hello Andrew

We do make connectors which are used on the PCI systems.

However we do not know which ones you are referring to, so we will not be able to help you with the information given.

You should contact the PCI system manufacturers for the information.

So I sent back a rather lengthy email referencing this thread, what we have found, what we suspect, our frustration, etc - I won't reproduce the email here (TLDR), but suffice to say I was polite, but did express the frustration (politely). Hopefully the thread and my email will be read, and someone will help in our efforts.

#### RDSCANNING

##### New Member
You may be able to use the Datasheet Archive search to find part numbers.

For example typing this in the search returns several molex parts. Hope this helps.

8-pin "PCI-E" power connector