PSU for dual CPU

TheThirdMan

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Sep 17, 2013
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Hey guys,

I was wondering what PSU people used for their own build servers and workstations with dual CPUs? Looking at some other forums they say you can use any PSU and get a molex to 4 pin/8 pin CPU power adapter like this and that will work. Just wanted to hear what you guys thought. I was thinking of getting a corsair 600w CXM builder PSU and get one of those adapters for the second PSU. The server is going to be used for rendering over a network, so the only components are two 60w xeons and an SSD, that's it, so i can't imagine i'd need more power than 600w.
 

sotech

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Jul 13, 2011
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We use Seasonic 400W Platinum fanless PSUs in the last couple of dual-socket G34 builds we have done. Excellent efficiency, not super expensive and ample headroom with two 6128 HEs+64GB reg RAM + misc add-in cards + SSDs for OS.

If you want more headroom they have higher-wattage models - for our setup the 400W sits in the sweet spot with regard to efficiency so it is a good match. We use an 80mm fan on the side of the unit (in a 2U case the fanless aspect doesn't work so well as a lot of the ventilation holes sit against the top or bottom of the chassis). The 6128HEs are 85W TDP from memory.
 
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cactus

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Jan 25, 2011
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I normally use this site two get a rough estimate of what wattage I need and get something 50 to 100% larger depending on expect usage to keep the load in the 20 to 80% range. If it is going to idle a lot choose something lower; if it is going to be under 100% load a lot go higher.

I am partial to Seasonic's when getting consumer PSUs. I have had good experience with Gold Seasonic 750s for when I owned an SR-2 for folding(Dual OC L5640s). I have also used an EarthWatts Green EA-380D with dual Opti 6128s and dual E5530s. I have build 3 computers with the Seasonic fanless model line sotech mentioned, but none were dual CPU (2x Haswell + Quadaro K4000 workstations 400W and a 4770K with GTX780 desktop 520W). Currently running my servers are a Supermicro 1u Platinum(~600W and quiet) and a Zippy 1+1 Silver(<500W and quiet).
 

TheThirdMan

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Sep 17, 2013
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London
We use Seasonic 400W Platinum fanless PSUs in the last couple of dual-socket G34 builds we have done. Excellent efficiency, not super expensive and ample headroom with two 6128 HEs+64GB reg RAM + misc add-in cards + SSDs for OS.

If you want more headroom they have higher-wattage models - for our setup the 400W sits in the sweet spot with regard to efficiency so it is a good match. We use an 80mm fan on the side of the unit (in a 2U case the fanless aspect doesn't work so well as a lot of the ventilation holes sit against the top or bottom of the chassis). The 6128HEs are 85W TDP from memory.
Interesting you use a fanless one. I remember reading a roundup 5 or 6 years ago about fanless PSUs in CustomPC magazine and their conclusion was that fanless PSUs weren't reliable enough at the time. I guess things have moved on since then! That one's only got good reviews.

I normally use this site two get a rough estimate of what wattage I need and get something 50 to 100% larger depending on expect usage to keep the load in the 20 to 80% range. If it is going to idle a lot choose something lower; if it is going to be under 100% load a lot go higher.

I am partial to Seasonic's when getting consumer PSUs. I have had good experience with Gold Seasonic 750s for when I owned an SR-2 for folding(Dual OC L5640s). I have also used an EarthWatts Green EA-380D with dual Opti 6128s and dual E5530s. I have build 3 computers with the Seasonic fanless model line sotech mentioned, but none were dual CPU (2x Haswell + Quadaro K4000 workstations 400W and a 4770K with GTX780 desktop 520W). Currently running my servers are a Supermicro 1u Platinum(~600W and quiet) and a Zippy 1+1 Silver(<500W and quiet).
Thanks for the link! It gives me 320W at 100% load, so the 600w PSU should be fine. That's an interesting list of PSUs. I haven't heard of Zippy PSUs. The Earthwatts at that wattage might be a little too underpowered if I'm only going to have this workstation running at 100% though?

How are you guys getting two CPU connectors out of these power supplies? It looks like they only have 1 cpu connector each. Are you using an adapter on a molex?
 

mrkrad

Well-Known Member
Oct 13, 2012
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get a mac pro, it's so freaking quiet you have to check yourself, then if you want, watercool it ;)

nothing comes close with dual 6 core!
 

vegaman

Member
Sep 12, 2013
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Auckland, New Zealand
Zippy is your main choice if you want to go redundant with a standard form factor. Pretty much every thing else is an odd size to fit a particular case.
Otherwise I'd recommend Seasonic. They're not too expensive and very well made/reliable. Others can be good but you have to look up who makes each model because a lot of companies use multiple OEMs for their power supplies.
 

TheThirdMan

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Sep 17, 2013
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London
get a mac pro, it's so freaking quiet you have to check yourself, then if you want, watercool it ;)

nothing comes close with dual 6 core!
I had a mac pro, dual 2.8ghz quad core. My favourite PC ever. They're incredibly cheap on ebay now too! But not really useful for what I'll be using it for.

Zippy is your main choice if you want to go redundant with a standard form factor. Pretty much every thing else is an odd size to fit a particular case.
Otherwise I'd recommend Seasonic. They're not too expensive and very well made/reliable. Others can be good but you have to look up who makes each model because a lot of companies use multiple OEMs for their power supplies.
I'll look into Zippy PSUs. Though the case I'll be using will just be a standard ATX case with E-ATX support for the 5520 mobo i'm using. Do they do dual CPU PSUs in ATX form?

For the seasonics- these don't have two CPU connectors for the motherboard do they? So how do I get power to both CPUs with these PSUs? Can i just use a molex to 8 pin adapter?
 

sotech

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Jul 13, 2011
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For the seasonics- these don't have two CPU connectors for the motherboard do they? So how do I get power to both CPUs with these PSUs? Can i just use a molex to 8 pin adapter?

I either use a Molex->EPS or repin one of the graphics outputs to an EPS end.
 

vegaman

Member
Sep 12, 2013
60
3
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Auckland, New Zealand
Zippy does quite a range of PSUs, including standard ATX and mini redundant - which are ATX sized but the mounting is a little different (screws around the edges instead of into the back) so the modules can be removed/replaced. I'm not sure of the connectors on them though sorry.
With either choice you'll be able to use an adapter if you need to though.
 

TheThirdMan

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Sep 17, 2013
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I either use a Molex->EPS or repin one of the graphics outputs to an EPS end.
Ah, that molex-EPS looks like the thing i need! Thanks.

Zippy does quite a range of PSUs, including standard ATX and mini redundant - which are ATX sized but the mounting is a little different (screws around the edges instead of into the back) so the modules can be removed/replaced. I'm not sure of the connectors on them though sorry.
With either choice you'll be able to use an adapter if you need to though.
Thanks for the help!
 

sotech

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Jul 13, 2011
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Ah, that molex-EPS looks like the thing i need! Thanks.

Thanks for the help!
One word of warning - we did try a couple of super-cheap eBay molex->EPS adapters a few months back and found that some of them don't have pins which are as firmly installed as one might like... meaning that after light tension was applied a few times the grounds fell out. Would not have been pretty had it happened when the power was on. The pin flanges weren't catching on the plastic.

Check before installing :)
 

TheThirdMan

New Member
Sep 17, 2013
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London
One word of warning - we did try a couple of super-cheap eBay molex->EPS adapters a few months back and found that some of them don't have pins which are as firmly installed as one might like... meaning that after light tension was applied a few times the grounds fell out. Would not have been pretty had it happened when the power was on. The pin flanges weren't catching on the plastic.

Check before installing :)
Thanks for the warning. I did just bookmark an adapter off ebay but I'm looking at some from proper retailers now
 

cactus

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Jan 25, 2011
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On the Seasonic PSU that come with an 8-pin EPS and the 4-pin P4 12v, I used a P4->EPS. It is cleaner than the 4-pin molex type. With the EA-380, I used two P4->EPS because the EPS connector splits on that PSU.


get a mac pro, it's so freaking quiet you have to check yourself, then if you want, watercool it ;)

nothing comes close with dual 6 core!
Off topic but two questions: Do these do 3chan memory and can a normal videocard be used? I have used Mac laptops for a long while and wouldn't mind a Mac desktop.
 

TheThirdMan

New Member
Sep 17, 2013
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0
1
London
On the Seasonic PSU that come with an 8-pin EPS and the 4-pin P4 12v, I used a P4->EPS. It is cleaner than the 4-pin molex type. With the EA-380, I used two P4->EPS because the EPS connector splits on that PSU.




Off topic but two questions: Do these do 3chan memory and can a normal videocard be used? I have used Mac laptops for a long while and wouldn't mind a Mac desktop.

They have to have mac specific graphics cards, at least when booting into mac os. I believe some people could use standard graphics cards when using bootcamp and windows though.

The 6 cores do 3chan memory, otherwise for the dual and quad cores, it's dual channel i think.
 

mrkrad

Well-Known Member
Oct 13, 2012
1,244
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you can rob a RPS from a DL320/DL160, it is industry standard plugs. I got one for 50 bucks (including two power supplies). keep an eye out, - servers that were not quite servers came with really compact (shuttle) sized RPS options! cheap. plus you can push RPS over the rated amps you will no longer be redundant