Question Connect 2x 4-pin power (different sources) to one 8-pin EPS-12v

BrunoCzar

Reputable
Feb 18, 2019
12
1
4,515
Hi,

Recently I acquired a dual slot motherboard, with two Xeon processors, it has 2x 8-pin slots for cpu power. I want to use on this set one 850w Seventeam PSU that currently has only one 8-pin connector. This configuration is for test only, I do have one 1200w EVGA Platinum, but I don't want to shutdown my main system without testing the new set first.

I got 2x adapters molex to 4-pin EPS-12V, I was afraid that only one molex could overheat. (the 5v cable is isolated).
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My problem now is that I realized that the plugs scheme is inverted on the slot. The first four plugs are square - rounded, rounded - square. But the other ones are rounded - square, square - rounded.
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Two adapters however are the same, like twins.
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I noticed that all 12v cables are connected on the same side, and all neutral cables on the other
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My guess is that the plugs are inverted to stop people from connecting one 4-pin cable on the wrong side of the slot in a 8-pin motherboard, but I'm not sure.

I wonder if someone that understand of this connectors, could say if is safe to plug both adapters, scraping the square plugs maybe. I saw some plugs on the web where the 4 plugs on the right were all rounded. Or if the best choice is to connect just one adapter in the left 4 holes.

Processors model are Xeon® E5-2650 v2 with a TDP of 95w.
 

BrunoCzar

Reputable
Feb 18, 2019
12
1
4,515
Well, just to close to topic.

I scraped the second adapter connectors with sandpaper and plug them in the motherboard. Each adapter was connect to an independent molex cable coming out from the PSU.
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I kept the system under test for over 30 minutes, I touch with my finger the most critical segment (the single cable from the emendation and the molex connector) no signal of heating.
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These are the images from the setup showing both cpus and Hyper-Threading enabled and some populars programs. For tests purposes I used one small 120gb SSD with Windows 10 pro not activated. I believe that the tests were very successful and now I will plan the permanent migration.
My test config:
  • MOB: JingSha X79 dual slot.
  • CPUs: Xeon 2650 v2 2600 MHz 8 cores 16 threads.
  • SSD 120gb Intel.
  • GPU Geforce Gigabyte 1070 Mini Itx.
  • PSU: Seventeam 850w

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