missing an 8pin cpu connector

Discussion in 'Power Supplies' started by SticKx911, Dec 16, 2014.

  1. SticKx911

    SticKx911 2[H]4U

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    I just bought a cx750 and it only has one cpu 8pin. I'm going to be running a z87 board that requires 2. What's the best route? I don't think I can use the 8-pin from my old silverstone. I'm also not sure if I can find a stock corsair 8 pin. That leaves me with adapters. So I can do molex>cpu or just an 8 pin>2x8pin... I don't plan on any crazy overclocking, but I didn't buy a k series to leave it stock either.

    from what I can find it seems the board will run without both so I'm thinking the splitter might be safer than I originally thought.

    Id like to find a states side version of this

    Sorry for the dumb question. My first foray into intel territory since my c2d so I was unprepared for the extra power need.
     
    Last edited: Dec 16, 2014
  2. Araxie

    Araxie [H]ardness Supreme

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    I would use the 8pin to 2x8pin just for the sake of use less PSU cables as possible and have better cable management =D..
     
  3. Tsumi

    Tsumi [H]ardForum Junkie

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    You don't need to connect that second 8 pin. Your CPU will never draw enough power to need it unless you do LN2 runs.

    The point of having two 8 pins is to reduce the amperage going through each pin, thus reducing energy loss at each pin and potential heating from too much amperage. Getting an 8 pin splitter defeats that purpose as it still needs to go through that first set of pins, and actually makes it worse by adding a second set of pins to go through as well as more wire to go through.
     
  4. primetime

    primetime [H]ardness Supreme

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    this kinda makes sense to me......if the other jack needs the power it will certainly pull a load if it needs to.....maybe it will balance the load if both jacks are hooked up:Dgood guestion
     
  5. Jorona

    Jorona 2[H]4U

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    Yup
     
  6. Tsumi

    Tsumi [H]ardForum Junkie

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    Did you read my post at all? If so, you would realize using a splitter is not a benefit in any shape or form. At best it does nothing, at worst it makes things worse.
     
  7. primetime

    primetime [H]ardness Supreme

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    I read it....I just wasn't 100% sure i agreed with that statement.....but im wrong all the time:D
     
  8. Tsumi

    Tsumi [H]ardForum Junkie

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    It's quite simple really.

    The whole point of using two 8 pin connectors is to distribute the load among the connectors. But if you have to go through the first connector, then you're getting the restriction from those connectors PLUS the second set of connectors.

    It's like going from a 1/2" hose to a 1" hose. Sure, you have less restriction from the 1", but you're still limited by the 1/2".
     
  9. primetime

    primetime [H]ardness Supreme

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    not saying i don't believe you.....i just love to experiment and most time it proves someones else idea correct...but hey someones got to do it...j/k...actually im betting the mb manual says the exact thing you said to be honest
    think about this for just a second though......all these 12 volts wires coming from a single rail in the power supply (in some cases) and aside from overloading the wire and or plugs in question, a part of me would always wonder if it could help...but i agree your more than likely correct than i am
     
  10. Tsumi

    Tsumi [H]ardForum Junkie

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    The thing is, internally, the PSU is designed to be able to deliver its entire rated power to the wires, in the case of most modern PSUs, the modular board. So that's not the bottleneck there. The bottleneck is in the wires from the PSU to the components, and the connectors that make up those wires. The PSU is the giant water main. The connections are the splits from the main. If you have two splits from the main going to the same place, you can provide more. But if you have one split, then you split that one split, you're still bottlenecked by the initial split unless the splits combined are smaller than the first one.
     
  11. primetime

    primetime [H]ardness Supreme

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    wires and connectors are rated for a certain current load...now as to whether using the splitter overloads the circuits as it may is an unknown factor without measuring the load on each cable and you would basically have to destroy the splitter to check each wire for max load...they probably do design each cable for a max load to not overheat the connectors and or wires so your statement holds water...but part of me just wonders.......i do know heat is a tell tell factor for any overloaded connector or wire so i imagine if it felt hot to the touch in any way....you were right all along...keep up the good info:)

    very unrelated picture [​IMG] but it looks like but not necessarily and overloaded wire and connector (i would hate to see this any where in my power distribution) i guess if one had a clamp on metter like this it would answer a great many questions as to how much current draw on each wire......i may have to pick one up just to add it to my tools but unlikely many of us have them or even care for that matter http://www.amazon.com/Auto-ranging-Digital-Clamp-Meter/dp/B001VGND88 this little gizmo http://www.amazon.com/Extech-480172-AC-Line-Splitter/dp/B0000YHN9W/ref=pd_bxgy_hi_text_y could be pretty usefull as well (if only money grew on trees lol) Im probably in the minority of people that even finds these kinds of tools cool
     
    Last edited: Dec 20, 2014
  12. Tsumi

    Tsumi [H]ardForum Junkie

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    Yes they are rated for a certain load. But the point is, if you have a splitter at a connector that is rated at a certain load, to two connectors rated for double the load, you're still constrained by the first connector at the lower load. You don't magically double the rated power of the first connector by using splitters. It just doesn't work like that.
     
  13. jojo69

    jojo69 [H]ardForum Junkie

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    [​IMG]

    what Tsumi said
     
  14. primetime

    primetime [H]ardness Supreme

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    oh come on......really.....its all just theoretical guess since unless you have measured the power draw then theres no way to prove the ideo one way or the other...lets be mature
     
  15. SticKx911

    SticKx911 2[H]4U

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    lol. My only argument against would be if the 8pin from my psu was actually made from quality wire and could support the load vs many that use crap so the dual is to weed out the junk ones. :)

    I just went with the one 8-pin and it seems to work fine. I got a 1ghz bump on auto voltage (0.864 on cpuz) so I can live with that. Anything higher needs more volts so I'll just stick with this for now.

    Thanks for all the inputs!
     
  16. Tsumi

    Tsumi [H]ardForum Junkie

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    There's no theory about the physics of electricity. Electricity by this time is well understood, at least on the macro scale for power transmission. You keep thinking ifs and butsÂ… THERE ARE NO IFS AND BUTS TO ANYTHING I SAID. everything I have said are well documented facts. No theory, no guesswork, facts. How about you be mature enough to accept these facts? Or even more maturely, learn the basics of electrical physics. This is not rocket science.

    ... What? I understood nothing from that first paragraph.
     
  17. jojo69

    jojo69 [H]ardForum Junkie

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    you are free to your own opinions, but not to your own facts

    thanks for playing
     
  18. Skillz

    Skillz [H]ard DCOTY 2017

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    The more connections on the same run = more possibility for resistance

    Resistance = bad

    With that being said. You'll be fine with one of those connectors unless you intend to go for 6+Ghz speeds on that processor.
     
  19. SticKx911

    SticKx911 2[H]4U

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    It wasn't really making a good point anyway. I'll make an extreme, non-realistic example to illustrate the crappy thought I had. If my psu had 0 gauge wire, a splitter would suit fine as the original run could easily support the amperage, but the idea is moot anyway as no psu has crazy gauge wiring.... :D


    I was just thinking aloud more or less, sorry to add to the fodder.
     
  20. Tsumi

    Tsumi [H]ardForum Junkie

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    It's not the wiring that's the concern as much as it is the pin connections. The wire resistance is generally negligible to the connector resistance. Unless you had some really thin wires.
     
  21. primetime

    primetime [H]ardness Supreme

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    what facts have you posted? nothing....you want to teach us? what are the 8 pin connectors rated for wattage wise? and whats the exact resistance added from the connector? if it were as bad as you claim.....modulare supplies would never have been started from the get go...cause omg the modular connector ads too much resistance:rolleyes:....you just blowing hot air imo.....im all ears if you want to post real facts or data sheets but im not holding my breath on this one
     
  22. Tsumi

    Tsumi [H]ardForum Junkie

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    Great argument... not. Don't accuse others of being immature when you are being extremely immature yourself. And nothing you said here relates to anything we have stated.
     
  23. primetime

    primetime [H]ardness Supreme

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    Well we can agree to disagree.......have a ice day:)
     
  24. Tsumi

    Tsumi [H]ardForum Junkie

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    No, any reasonable person will agree that you are wrong, and that you don't want to admit that you're wrong.
     
  25. Dangman

    Dangman Ninja Editor SuperMod

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    Stay on topic and be respective to one another as per rule #1 of the [H]Forum Rules.
     
  26. primetime

    primetime [H]ardness Supreme

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    Sure thing Dangman...I believe the op's question was more than answered anyway;)
     
  27. Jorona

    Jorona 2[H]4U

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    This thread reminds me of Climate change "Skeptics"

    You can believe what you want, but you can't change fact.
     
  28. primetime

    primetime [H]ardness Supreme

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    Hey i resemble that remark.....I always believe myself before proving the other person correct.....once in a blue moon i get it correct out of luck:)
     
  29. plugwash

    plugwash [H]ard|Gawd

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    If the connectors are good quality and in good condition then the wire resistance and contact resistance will likely be comparable. Mini fit HCS is specified as having a maximum initial resistance of 10 milliohms.18AWG wire is about 20 milliohms per meter, so at half a meter the resistance of the cable would be comparable to the maximum specified initial resistance for the connector pin.

    However wire resistance is highly predictable and spread over a large area so the heat it produces is not much of an issue. Contact resistance on the other hand is concentrated on a small area, will vary a lot with the quality of the connector pin and how it has been treated and is often subject to nasty positive feedback where a high resistance connection gets hot which changes the properties of the metal increasing the contact resistance further.

    Getting back to the subject of the thread an 8 pin 12V connector should be good for ~400W if made with genuine molex HCS parts and even made with cheap parts it should be good for any reasonable overclock of an LGA115x CPU.
     
  30. primetime

    primetime [H]ardness Supreme

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    Thank you for the very good explanation....definitely opened my eyes:)