Help finding power supply with dual 8-pin EPS connectors?

mattlach

Member
Aug 1, 2014
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Hey all,

There isn't a power supply specific forum, so I hope this belongs here.

My server has been up and running for a few years now with a desktop power supply with only one 8pin EPS connector. I connected the second one by using a 6pin PCIe graphics plug to 8pin EPS adapter.

I have since found out that this is not really a good idea, especially now that I am about add a couple of PCIe expansion cards that will draw a good deal of power through the slots.

So, to this end, I am looking for a replacement power supply. I'm going to try to continue using a desktop power supply, because I am familiar with the form factor, know it fits my case (Norco RPC4216) and because they tend to be cheaper.

What I am ideally looking for is something like this:
  • Dual EPS 8-pin plugs (without using adapters)
  • 24 Pin Motherboard plug
  • Approximately 750W (~=/- 100W)
  • Reasonably efficient (Platinum would be nice, after all this box is on 24/7)
  • Modular design would be great too, to help clean up the rats nest of wires in there.

I appreciate any suggestions!
 

T_Minus

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Most modular power supplies will have the cable available for $4-8

I'm running numerous seasonic with 2, I had to buy the 2nd on all but the $$$ models.
 

mattlach

Member
Aug 1, 2014
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Most modular power supplies will have the cable available for $4-8

I'm running numerous seasonic with 2, I had to buy the 2nd on all but the $$$ models.
Ahh, good point! I have a SilverStoneStrider 1200 Gold PSU in my workstation (this is the only modular power supply I have) and I did notice in the past, that the PSU side of the modular cables appears to be universal...

If all Silverstone power supplies use the same format, I might even have a spare 8pin EPS cable in the box from this power supply, so I don't have to buy another one. 9If it only werent so difficult to tell 8-pin EPS and 8pin PCIe apart...
 

T_Minus

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They shouldn't be the same iirc

Also, using a splitter is fine as long as the PSU rail can support it.
 

mattlach

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Aug 1, 2014
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They shouldn't be the same iirc

Also, using a splitter is fine as long as the PSU rail can support it.
That's the opposite of what I have read.

I've heard horror tales of people wrecking motherboards and power supply connectors by overloading the cables in the connectors, and melting them, and the connector on the motherboard.

In fact, the manual for my Supermicro X8DTE even says warranty is void, unless used with a power supply with two 8 pin EPS plugs.

The reason I am concerned about my 6pin PCIe to 8 pin EPS 12v adapter is that the 6pin PCIe power is listed as max 75W, whereas the 8 pin EPS connector is listed as max 336 watt. There is a potential to accidentally significantly over draw the PCIe connector by doing this.

Granted, most of the horror stories I have heard have been from people who do bitcoin mining, and put some serious power through their systems.

With two relatively low power Xeons (L5640) I probably shouldn't ahve to worry too much, but still, better safe than sorry, especially since I'm adding two Quadro 2000's at up to 62.5W each, that pull all their power over the PCIe slot, and already have two LSI 9211-8i's, a Brocvade BR1020 and a quad port Intel Pro/1000 PT in there...

So you think that Silverstone uses a different PSU side plug design for their different PSU's?
 

Phate

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Jun 5, 2015
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I'm have an EVGA SuperNova 1050 ES and a Corsair AX760 in my two servers.

Both come out of the box with full support for dual CPUs and had 2 EPS cables.
 

T_Minus

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I should have given more info, sorry.

I don't use or have any experience using a PCIE power for the motherboard, if it's not rated for the load then don't do it.

They do make the EPS splitter -- and depending on your CPUs, PSU, rail and wire gauge it may be 100% within spec to do that. I also think they have some molex to EPS (single and dual) that once again will work depending on the wire, cpu, psu and rail.
 

Patriot

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Apr 18, 2011
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They make EPS splitters, they also make firestarters... They both accomplish the same.
Don't use anything not from original psu manufacturer.
No splitters, no adapters... maybe vampire plugs for sata if you calculate the load correctly.

Every plug adds resistance, cables often even have inline caps in them now, by lengthening or shortening those cables you risk putting the psu out of tolerance/spec...as well as adding a high resistance point for starting a fire.
 

RobertFontaine

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Dec 17, 2015
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Tougher yet is finding a psu with 2 8's plus a 4 pin for power.

Retail PSU's vs Commercial PSU's is an amazing difference in build quality and power quality. Commercial PSU's have test points, real caps, and are even designed to be serviced. Retail junk, even expensive retail junk is designed to be disposable.

If there were decent quality harnesses for some of the PSU's designed for dual hot swap enclosures we would be a lot better off for home labs. I suspect there is a small opportunity for a harness maker... Ignoring the American desire to sue anyone or anything...

I could then buy a couple of 2000W SM power supplies for the price of a "gaming" psu.

I went googling for custom sm harnesses :)
Why you should never build a backblaze pod
 
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T_Minus

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You can buy SM power backplanes on ebay too, the problem is the LONGGGGGGGGGGGGGGGGG power supplies :)
 

FunkyRider83

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Jan 31, 2016
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EVGA SuperNova 750 G2

It's what I used in my dual 2670 build. It becomes passive when load/temp is low. Has 2x 8-pin EPS, 4x 8-pin PCI-E and ample of SATA/Molex
 

Terry Kennedy

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You can buy SM power backplanes on ebay too, the problem is the LONGGGGGGGGGGGGGGGGG power supplies :)
Yup. There seems to be a relatively large surplus market due to people upgrading chassis to bigger supplies. I bought a bunch of these to do this to them:





Not recommended for the faint of heart, or those without the proper tooling and a good power supply tester. :eek:
 
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noths

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I 've read this thread very carefully because I plan to use my PC Power & Cooling silencer 750w with a SM X9DAI and 2 E5 2670 (we all know I got the tip from great deals). As my PSU has only 1 8pin EPS and 1 4pin ATX I 'm going to use a Startech adapter. Do you think that I 'm risking too much? Thank you.