[SOLVED] Is the Extra 4 pin CPU connector on an Asus crosshair VIII Hero necessary for a 3900x to work properly?

goki

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Sep 1, 2019
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Greetings

Is the Extra 4 pin CPU connector on an Asus Crosshair VIII Hero necessary for an 3900x to work properly?

My psu doesn't have an additional cpu connector should I buy a new psu just for that 4 pin connector?

The manual said is optional, would do I really need it?

Thanks in advance
 
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Solution
Thanx for the help, you mention an adapter. I have an extra pcie slot on my psu. Are there some kind of adapters pcie to cpu? my PSU is a Seasonic Focus SSR-750FM.
This is the kind of adapter to get:

https://www.amazon.com/8-Pin-EPS-12V-Female-Splitter-Cable/dp/B01JC4D3NU

A 'Y' adapter that converts the single 8 pin to two 8 pin connectors.

I'm assuming you mean an 8 pin EPS-12V connector, not a 4 pin ATX-12V. That Seasonic should come with at least one 8 pin or perhaps a ganged pair of 4 pin connectors (4 + 4). I think it also has a socket for a second 8 pin EPS cable, if you could get one of those (check the box your PSU came in for some loose cables.)

Even for a 3900x an extra 8 pin EPS is superfulous unless...

Aeacus

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Well, if you don't OC the CPU, you should be relatively safe. Though, i'd still add the 2nd 4-pin EPS12V just to be safe.

However, if you do plan to OC the CPU, extra 4-pin EPS12V is mandatory since it's often needed to get a stable OC on CPU (it provides additional power to CPU and stabilizes the voltage).

Here, i'd go with new PSU, rather than buying adapter for it. For a good quality PSU, look towards any Seasonic unit. E.g Focus/Focus+ or PRIME/PRIME Ultra.
 

goki

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Sep 1, 2019
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510
Thanx for the help, you mention an adapter. I have an extra pcie slot on my psu. Are there some kind of adapters pcie to cpu? my PSU is a Seasonic Focus SSR-750FM.

I found this online https://shopee.com.my/20cm-GPU-PCI-...n-Power-Adapter-Cable.-i.132107909.2356961136 not sure is legit tho. I don't want to fry the MOBO.

Well, if you don't OC the CPU, you should be relatively safe. Though, i'd still add the 2nd 4-pin EPS12V just to be safe.

However, if you do plan to OC the CPU, extra 4-pin EPS12V is mandatory since it's often needed to get a stable OC on CPU (it provides additional power to CPU and stabilizes the voltage).

Here, i'd go with new PSU, rather than buying adapter for it. For a good quality PSU, look towards any Seasonic unit. E.g Focus/Focus+ or PRIME/PRIME Ultra.
 
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Thanx for the help, you mention an adapter. I have an extra pcie slot on my psu. Are there some kind of adapters pcie to cpu? my PSU is a Seasonic Focus SSR-750FM.
This is the kind of adapter to get:

https://www.amazon.com/8-Pin-EPS-12V-Female-Splitter-Cable/dp/B01JC4D3NU

A 'Y' adapter that converts the single 8 pin to two 8 pin connectors.

I'm assuming you mean an 8 pin EPS-12V connector, not a 4 pin ATX-12V. That Seasonic should come with at least one 8 pin or perhaps a ganged pair of 4 pin connectors (4 + 4). I think it also has a socket for a second 8 pin EPS cable, if you could get one of those (check the box your PSU came in for some loose cables.)

Even for a 3900x an extra 8 pin EPS is superfulous unless you're going to overclock on LN2. That's when voltages used and currents pulled are insane to us mortals seeking 24-7 workable and stable overclocks using above ambient cooling methods.
 
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Solution

goki

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Sep 1, 2019
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Thanks for the tip, the pcu only comes with a single 8pin EPS . that split into 2 4 pin connectors I have a free pcie module tho. I think i'll get that Y adapter later if i need it. I dont think ill be doing any LN2 oc or even light oc anytime soon anyway.

I also found this online https://shopee.com.my/20cm-GPU-PCI-...n-Power-Adapter-Cable.-i.132107909.2356961136 not sure is legit tho. I don't want to fry the MOBO.



This is the kind of adapter to get:

https://www.amazon.com/8-Pin-EPS-12V-Female-Splitter-Cable/dp/B01JC4D3NU

A 'Y' adapter that converts the single 8 pin to two 8 pin connectors. I'm assuming you mean an 8 pin EPS connector.

That Seasonic should come with at least one 8 pin or perhaps a ganged pair of 4 pin connectors. I think it also has a socket for a second 8 pin EPS cable, if you could get one of those.

Even for a 3900x the extra 8 pin is superfulous unless you're going to overclock on LN2. That's when voltages used and currents pulled are insane to us mortals seeking 24-7 workable and stable overclocks using above ambient cooling methods.
 

Aeacus

Titan
Ambassador
Thanx for the help, you mention an adapter. I have an extra pcie slot on my psu. Are there some kind of adapters pcie to cpu? my PSU is a Seasonic Focus SSR-750FM.

I found this online https://shopee.com.my/20cm-GPU-PCI-...n-Power-Adapter-Cable.-i.132107909.2356961136 not sure is legit tho. I don't want to fry the MOBO.
Well, your Seasonic unit comes with one 4/8-pin EPS12V cable (source). Just connect both connectors to the MoBo CPU power connector (don't split them) and you're golden. There's no need to get any adapter whatsoever.

4/8-pin EPS12V cable MoBo side connector looks like so:
eps4plus4.jpg
 
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Thanks for the tip, the pcu only comes with a single 8pin EPS . that split into 2 4 pin connectors I have a free pcie module tho. I think i'll get that Y adapter later if i need it. I dont think ill be doing any LN2 oc or even light oc anytime soon anyway.

I also found this online https://shopee.com.my/20cm-GPU-PCI-...n-Power-Adapter-Cable.-i.132107909.2356961136 not sure is legit tho. I don't want to fry the MOBO.
I'm not sure what you're doing... don't get any cable that connects to a PCIe close to the CPU or vice-versa, not even through an adapter. Just don't. Use only an EPS-12v cable on the CPU connectors and only a PCIe on the GPU.

Your PSU seems modern and full featured, it should come with all the cables needed to attach to a single 8 pin EPS-12v connector and a PCIe GPU connector using the cables that come with it. It may have only one 8 pin EPS (or a 4 + 4); you can adapt that (using an adapter like i showed before) if seeing that empty 8 pin header makes you nervous but it's really not needed unless overclocking on LN2.

But a good rule of thumb is never try to connect PCIe to CPU or CPU to PCIe connectors. Not even through 'designed for it' adapters, not unless you know the pin-outs and how to double check that they are wired correctly. Those adapters are made by the cheapest fly-by-night assemblers and even though errors may not be common all you need is the single bad one they made that year and it ruins your hardware. Instead, use the cables that come with your PSU if possible.
 

goki

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Sep 1, 2019
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Thanks for the advice so Y splitters are the safer option . Il rather not risk it tho, if is only needed for LN2 overclocking. But if ever need it i'll go with the Y adapters.
Just to make the post clearer Im leaving empty the 4 pin eps not an 8 pin.
po04gK2ij






I'm not sure what you're doing... don't get any cable that connects to a PCIe close to the CPU or vice-versa, not even through an adapter. Just don't. Use only an EPS-12v cable on the CPU connectors and only a PCIe on the GPU.

Your PSU seems modern and full featured, it should come with all the cables needed to attach to a single 8 pin EPS-12v connector and a PCIe GPU connector using the cables that come with it. It may have only one 8 pin EPS (or a 4 + 4); you can adapt that (using an adapter like i showed before) if seeing that empty 8 pin header makes you nervous but it's really not needed unless overclocking on LN2.

But a good rule of thumb is never try to connect PCIe to CPU or CPU to PCIe connectors. Not even through 'designed for it' adapters, not unless you know the pin-outs and how to double check that they are wired correctly. Those adapters are made by the cheapest fly-by-night assemblers and even though errors may not be common all you need is the single bad one they made that year and it ruins your hardware. Instead, use the cables that come with your PSU if possible.
 
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