Justifier

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Oct 25, 2009
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Hello everybody,

I have registered to the forums and wanted to ask this question directly to you because it is blowing my mind. I have just bought a P55-UD3R. My other system elements are
CPU: i5 750
GPU: Ati HD5850
HDD: Seagate 500gb sata
RAM: Kingston 4gb HyperX 2000mhz dual channel
PSU: FSB Bluestorm 2 500W
And I am using Vista Home Premium

Anyway, when I made the installation of my pc, I have realized that my psu has not a 8-pin cpu power connector. Instead there was a 4-pin cable. In the manual it says that 8-pin connector is for 2x4 cables but I may use the 2x2 cable to fill the 4 slots there. My question is that is it safe to use it like that? Considering that i will play high-end games which will consume lots of power. I have looked in internet for a while and some people says you can use it some says you can not. There is also an idea which is you can use 4-pins if you don't have a quad core. I am totally confused.
I am looking forward to your answer. Thank you.
 

SpidersWeb

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Aug 19, 2009
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You can't get dual core processors for your motherboard, so the 'only if you have a quad core' thing is a bit redundant. There are also 4 pin motherboards (like mine) that are known to overclock quads quite well.

The 8 pin connector allows for a second power rail, allowing more clean and stable power. That was it's idea, I can't be sure desktop power supplies actually use multiple rails. The only effect you might see with using 4 pin instead of 8 pin, is you may not be able to overclock quite as high.

If you run in to issues when doing heavy overclocking, then get a newer higher rated PSU (which will have the 8 pin and a bunch of PCI-E 8 and 6 pin plugs too). If you're not overclocking, then it's not an issue at all.

The 4 pin plug just slots in to the first 4 pins on the 8 pin plug, they are shaped, so you can't get it in the wrong end or around the wrong way.
 

johnnyq1233

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Aug 15, 2007
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Very good spider..the psu you have is probably an older version.
My Corsair vx550 has the 8 pin connector but my board only suports 4 so it breaks in half.
Don't worry about the other 4 pins just make sure you plug the 4 pin connector in the right spot.
On my old Foxconn it had to be the 4 closest to the processor....(yes it had the 8 pin block)
Hope this helps...JQ
 

Justifier

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Oct 25, 2009
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--------------------------------------------------------------------------------

Thank you for your answers. I am not planing to do some overclock in the next 1 - 1.5 year so it is not an issue for me right now.However having a better psu is a good idea but costly too. I also have a strange problem which I want to ask you.

I hear a stange noise coming from my psu. It is like tıssss tıss tıssss. It sounds like electrical not like a fan issue but i am not an expert on this. When I first hear it I was on the installation screen of vista to my new HDD. After I realized that I knew something is not right. But I am not sure if it is coming from my psu or not. I can hear it clearer when I move closely to my psu.
Anyway I started some tests. First I changed my graphic card with my older one. It is an ati x1800 xl. But the noise was still there. Then I put my new card back and changed my HDD this time with older one which is samsung 160gb sata. The noise was still there as well. I aslo think that there is not any stange noise during system start but the second I see the vista logo and then my desktop, the noise comes.
Then I decided to test my psu this time. I removed everything and installed my old pc. As mainbord asus p5b, 2 gb kingston ddr2 667, intel core 2 duo e6420 and x1800xl + 160gb sata samsung. There wasn't any noise this time! It was just as I remembered. Stable and quiet. I even made a clear format-vista install.

Now here is my question: Is this stange noise related to my 4-pin issue? Have you heard anyhing about it or experienced?

If it is not related then what is wrong with my pc? We know that it is not about GPU or HDD. And I think rams are not capable of doing something like that. So is it about my new board or cpu. Or it is all about having insufficient power supply? By the way I am also using a UPS which is 650VA and 1.5 years old.( It saved my pc countless times from the voltage changes in my neighbourhood.) Is it aslo a factor here?

I know it was a long post but I really appreciate our help. Thank you guys.
 

SpidersWeb

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I know the noise you mean, but I don't technically know what causes it.
It'll be happening only in your new setup because your new setup will be consuming considerably more power. Becuse the 4 pin connector (ATX12) is a standard, it's unlikely this is the issue unless your power supply is failing to deliver the correct rated current (if the standard i5 needed a full 8 pin (EPS12), then gigabyte would not have allowed a 4 pin connection).

Personally I'd replace it just for peace of mind, as I usually associate that noise with a supply that is being strained or one that's on the way out. However since I just replace them, I've never investigated the actual cause (normally I put it down to age).

Hopefully someone can post up some actual facts of what causes that noise.
 

jkim

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Oct 27, 2009
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Yup, did it. I actually experimented and used just the 4-pin (2x2), a 4-pin (2x2) to 8-pin (2x4) adapter, and a new psu with the 8-pin (2x4). No difference noticed.
 

bilbat

Splendid
All the 1156 processors released so far are ninety-five watt TDPs - so if you figure the whole ninety-five going through the 2x2 (which it doesn't...), at five volts, you're looking at nine and a half amps per wire ([ 95 / 5] / 2 ); look at a standard wire ampacity chart:
http://www.powerstream.com/Wire_Size.htm
and you'll see this is easily accomodated by a twenty AWG wire (only thirty-two thousandths thick!); as the vast majority of PSUs modern enough to have a 2x2/2x4 setup use at least sixteen or fourteen AWG, you have no problem. I think the reason 2x4 is recommended for TDPs above a hundred is more for the sake of the board traces, than the wire/connector limitations...