4pin to 8pin OR dual molex to 8pin

[mars696]

Hello guys,
I have read a lot of similar questions but let me ask you something more...
The good old staff: my new mobo has a 8pin connector,but my psu has a 4pin connector.
I dont want to risk and plug the 4pin to the mobo as it is,so i search the web for a solution(except from buying a new psu ).

The most common answer is a 4pin to 8pin converter like this:
http://www.ebay.com/itm/ATX-4-Pin-male-to-8-Pin-Female-EPS-Power-Cable-Adapter-/110718428920?pt=US_Power_Cables_Connectors&hash=item19c75526f8

But i found also this:
http://www.ebay.com/itm/12V-Molex-4-to-8-pin-Desktop-PC-PSU-Supply-to-Motherboard-ATX-Power-Lead-Cable-/171202502834?pt=UK_Computing_CablesConnectors_RL&hash=item27dc76e0b2

I think that the second converter can handle more power,as each molex will connect to two separate cables coming from the power supply not one.

Which is the best solution,so i wont having any power problems even if i o/c my hardware?

 

[alexoiu]

Hi, A third option: http://s11.postimg.org/414beevpv/8_pin_EATX12_V_motherboard_power_connection.png

 

[mars696]

Thanks,
I have seen this option, but i dont trust it...just a state of mind...

 

[RealBeast]

Thanks,
I have seen this option, but i dont trust it...just a state of mind...

Using the 4 to 8 pin converter is electrically the same as just plugging the 4 pin cable into the 8 pin board connector.

With current CPUs you can do any of the above safely. THIS page has pictures of the 4 and 8 pin connectors with links to text on their specs and you can read about the difference and understand that any of the three options are fine.

 

[mars696]

Yes,this is the page i found the " two molex to 8pin" option.
But that part is that make me think:
""You can plug a 4 pin 12 volt power cable into an 8 pin EPS motherboard connector but there's no guarantee that it will work. If the motherboard expects only one 12 volt rail then a 4 pin 12 volt cable may work. If the motherboard expects two 12 volt rails (many dual CPU motherboards require one 12 volt rail per CPU) then it won't work. Even if the motherboard works with a 4 pin 12 volt cable, you are still only providing half of the current carrying capacity which would be provided by an 8 pin EPS cable. That can overheat both the motherboard connector and 4 pin cable. Scorched or melted connectors can be a result. A motherboard which has the 8 pin EPS connector expects a lot of current and you are taking a serious risk by plugging in a 4 pin cable. The 4 pin cable only fits at one end of the 8 pin EPS motherboard connector so you can't plug it in improperly. That is, it only fits into one end of the motherboard connector unless you force it. If the cable doesn't go into the socket easily then you're probably trying to plug it into the wrong end. But then again, it's not a good idea to try to run with a 4 pin cable in an 8 pin motherboard anyway.""

And a page later he propose the two molex to 8pin converter:
""If you don't have an 8 pin 12 volt cable then you can use the adapter shown above. It converts a couple of 4 pin peripheral power cables into an 8 pin 12 volt cable. If you use one of these adapters then be sure to plug the 4 pin peripheral connectors into separate cables coming from the power supply. If you plug them both into the same power supply cable then you are drawing all the power of the 8 pin 12 volt connector through a single 18 gauge wire. You can often get away with that but there's no reason to do it.""

 

[RealBeast]

So what motherboard and CPU are you using?

 

[mars696]

mobo:Gigabyte GA-78LMT-USB3
cpu: amd athlon ii x2 280

 

[RealBeast]

That is only a 65W CPU, and doesn't even come close to 192W under full load so there is no need worry. If it makes you feel better, buy the 2 molex to 8 pin adapter but you don't need it. The other adapter is the same as just plugging the four pin cable directly into half of the 8 pin socket, so there is no logic behind that one at all.

 

[mars696]

The TDP is the max amount of power dissipated by the processor under normal circumstances. It isn't the max amount of power that the processor can consume!!
I suppose that it is related ,but its not the same.

 

[alexoiu]

Here's a similar board with only 4 pin connector:
http://www.msi.com/product/mb/760GM-P23--FX-.html#/?div=CPUSupport
The extra power is necessary when higher consumption (OC or TDP). With that CPU you're fine with 4 to 8 pin.
But, if you still think that it's not safe, just get a PSU with an 8 pin connector.

 

[RealBeast]

The TDP is the max amount of power dissipated by the processor under normal circumstances. It isn't the max amount of power that the processor can consume!!
I suppose that it is related ,but its not the same.

No duh, but under full load the power use will not even approach that amount. Do a little research.

I give up, you obviously need the Molex splitter, although nobody else needs it.

 

[mars696]

That's seems ok...
I think you are right guys!
Is just the fear of the new build every time!!
Thanks for the answers!!

 

[RealBeast]

Take a look at THIS review of power use at the ATX12V under 2x Prime95 use and you will be more comfortable with a 4 pin connection. The old processors and some of the newer large or inefficient CPUs would be the only ones that would potentially need a full 8 pin connection.

 

[Aleksandar_2]

Take a look at THIS review of power use at the ATX12V under 2x Prime95 use and you will be more comfortable with a 4 pin connection. The old processors and some of the newer large or inefficient CPUs would be the only ones that would potentially need a full 8 pin connection.

i also have psu with 4 pin http://,but my mb have 8 pin cpu connector, I plan to buy i3 4170,the tdp is 54 w for this processor..is it safe to just plugging the four pin cable directly into half of the 8 pin socket?or it safer to buyhttp:// ??i use integrated graphic of cpu and one hdd ...thx

 

[Dark Lord of Tech]

Adapters are never a good idea with a low quality PSU.

 

[Aleksandar_2]

ok,is it safe to put 4 to 8 pin to mb? is there a possibility of damage to my CPU, MB?This is temporary for me, as I plan to get a new PSU as soon as possible...

 

[RealBeast]

ok,is it safe to put 4 to 8 pin to mb? is there a possibility of damage to my CPU, MB?This is temporary for me, as I plan to get a new PSU as soon as possible...

It is fine to connect a 4 pin PSU ATX12V CPU power connector to half of the 8 pins on your motherboard. I would not use an adapter, as it does nothing useful.

 

[Aleksandar_2]

ok,is it safe to put 4 to 8 pin to mb? is there a possibility of damage to my CPU, MB?This is temporary for me, as I plan to get a new PSU as soon as possible...

It is fine to connect a 4 pin PSU ATX12V CPU power connector to half of the 8 pins on your motherboard. I would not use an adapter, as it does nothing useful.

thx for reply,Is this power supply enoughhttp:// for cpu (i use integrated graphic) and one hdd

 

[RealBeast]

I would not use it myself as it only has 15A on the 12V rail and is a low end unit that could damage your components. I opt for quality brand units, however they cost more.