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The Power Supply Thread

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7 hours ago, Tybio said:

Quick question all, I'm getting a seasonic 650W for my new build, but it only comes with 6xSATA power, I need to run 3 5-in-3's that each take 2 connectors and 2 SSDs outside of the 5-in-3s.  In my old system I just had a sea of Molex splitters and ran off of two power supply lines...however I'm wondering if you can run 3x5-in-3 off one 6-pin connection to the power supply via an extender, or if I should split them between two (which would mean ordering another cable).

 

This will power 15 drives, Mostly 8+TB IronWolfs at this point.

Is it a modular psu? Then I would contact Seasonic customer service and ask them to send you a couple of sata power cables. You can replace a molex cable with it I think. I got them for my x-760 free of charge.

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1 hour ago, garycase said:

Not sure what you're referring to r.e. "... one 6-pin connector".   IF the voltages are correct and you wire them correctly, then yes, you could power one of the cages from that feed.    But if there's any doubt, I'd just use a splitter, which you KNOW is providing the right voltages to the right places :D

The Seasonic has a 6-pin connector on the PS side :).

 

I'm sure that the power supply can deliver the load, the reason I'm checking in is to make sure that the SATA cable can carry enough power for 3 5-in-3 cage from the power supply to them (2xSATA power connection for each cage).

 

 

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1 hour ago, dikkiedirk said:

Is it a modular psu? Then I would contact Seasonic customer service and ask them to send you a couple of sata power cables. You can replace a molex cable with it I think. I got them for my x-760 free of charge.

 

There is a post here about ordering extras, the PSU is this one: https://www.amazon.com/gp/product/B01HXYRJYK/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

 

so fully modular.  Another user posted a source for cables, perhaps I'll just get 2 more as the Seasonic comes with 2xSATA Power and 4xSATAPower.  I could home run all my devices with 4 of the 2x cables and never have to worry about power again.

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10 minutes ago, Tybio said:

Another user posted a source for cables

Make sure they are compatible. There is no standard pinout for modular power supplies. If you get cables that have the wrong pins on the PSU side then you could easily fry something.

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13 minutes ago, Tybio said:

The Seasonic has a 6-pin connector on the PS side :).

 

I'm sure that the power supply can deliver the load, the reason I'm checking in is to make sure that the SATA cable can carry enough power for 3 5-in-3 cage from the power supply to them (2xSATA power connection for each cage).

 

 

 

One SATA cable to power 15 disks? That's a truly huge startup current to handle. With 2 A startup current, it's 30 amps to handle during startup.

 

In general, you should avoid going over 8A / connector pin for Molex-type connectors. Each contact pin can handle up to 11 A but the cables used are normally dimensioned for 6-10 A.

 

And avoid going over 1.5A / connector for SATA-type connector pins.

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2 minutes ago, pwm said:

 

One SATA cable to power 15 disks? That's a truly huge startup current to handle. With 2 A startup current, it's 30 amps to handle during startup.

 

In general, you should avoid going over 8A / connector pin for Molex-type connectors. Each contact pin can handle up to 11 A but the cables used are normally dimensioned for 6-10 A.

 

And avoid going over 1.5A / connector for SATA-type connector pins.

 

Help me out, I don't think I'm following.  If startup is 2A then how could one avoid going over 1.5A for SATA power even with dedicated PS-drive modular cables?  (Not to mention that most modular PSUs only have 4/5 "accessory" connections for things like drives)

 

I'm sure I'm not following and we are somewhere in the middle.  Like for 15 drives use 3xSATA power split properly or somesuch.  Remember, the cages have 2xSATA power each, so by definition the best I can do is 2.5 drives per SATA power.

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15 minutes ago, Tybio said:

If startup is 2A then how could one avoid going over 1.5A for SATA power even with dedicated PS-drive modular cables?

 

Notice that I did write 1.5 for SATA-type connector pins. Each pin can handle 1.5A, but the SATA connector has three pins for each voltage so it can handle 4.5 amp for each voltage.

 

18 minutes ago, Tybio said:

Like for 15 drives use 3xSATA power split properly or somesuch.

 

With splitter cables, you can keep down the current/connector pin at the drive side. But you still have high currents on the PSU side of the cables, i.e. before the split.

 

When you run a high current through a connector, the connector gets hot. When it gets hot, it increases the problems with corrosion. And corrosion increases the contact resistance which means more losses and more heat.

 

Next thing is that a high load over some few cables means lots of voltage loss - and because computer equipment is constantly varying the load, there will be constantly varying voltage losses. So the disks will see less stable voltages and the filter capacitors will have to work harder.


So you do not want to feed 15 disks from a single cable out of the PSU.

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Got it, thanks for clarifying!

 

That's great information, I think what I'll do is use some Molex runs with SATA adapters, that way I can get it down to 5 drives per PSU run with one of the runs "splitting" to feed the two SSDs on the side.  I'd think that's going to be about as good as I can possibly balance things.

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If I am only running 4-5 HDDs max, will I be fine with a dual rail PSU?

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6 hours ago, 106 said:

If I am only running 4-5 HDDs max, will I be fine with a dual rail PSU?

 

Depends on the hardware  - but people could use way more than 4-5 HDD for many years when dual rail was the required/expected standard for PSU.

 

The implications of dual-rail or single-rail matters way more for people building 24-disk systems than for people building what is more or less a standard PC.

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What is the recommended PSU nowadays? Ive used seasonic and it has been nothing but trouble. A google on the net seems like its a common problem with seasonic. Even local Seasonic distributor has stopped selling seasonic products. the problem with seasonic is that, after a while, it cannot be turn on. you have to switch on and off rapidly until it switch on the pc. 

 

What about corsair? How much power do we need for full 24 drive(currently i have 15 drives) what model would you recommend?

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I've had nothing but good luck with Seasonic, I am surprised to hear you've had issues with their products. They make power supplies for many other companies who rebrand them with their own names. Corsair makes a decent product, but I have always sworn by Seasonic.

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I am looking to build a low power Unraid server using a J3455 or J4105 board and 4-6 8TB WD Red drives.  The board will support 4 drives or I can add two more through a PCIe SATA card.

 

I am struggling to find a power supply for a build like this due to finding it to be right between the gap of Pico PSUs and lower end 300-450W standard power supplies.

 

Will the largest Pico PSU handle a build like this?  I reached out to Mini-Box but their response was vague and did not give me much confidence.

 

What standard type of power supply would handle a build like this?  I would prefer something in the Gold range for efficiency reasons but am coming up short.

 

Finally, what would you expect the max wattage for a system like this to be?  Motherboard, 4-6 drives, SATA card, and 2-3 case fans?  The online calculators add up to 190-200 watts but that seems excessively high to me.

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You need to add up the max spin up current ratings in Amps of the drives (available on the manufacturer's page) on the 12V lines, take a reasonable good guess at the amps of the mb / addon cards on the 12V and compare it to the amp ratings on the 12V line from the powersupply.  

 

The wattage rating of any given powersupply is a meaningless value, because it is the sum of all the wattage of the various lines.  (IE: As an extreme example, nothing says that a manufacturer can't make a 1000Watt supply that is unable to handle the current required on the 12V line for 3 drives - although this won't happen in practice)

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3 hours ago, Squid said:

You need to add up the max spin up current ratings in Amps of the drives (available on the manufacturer's page) on the 12V lines, take a reasonable good guess at the amps of the mb / addon cards on the 12V and compare it to the amp ratings on the 12V line from the powersupply.  

 

The wattage rating of any given powersupply is a meaningless value, because it is the sum of all the wattage of the various lines.  (IE: As an extreme example, nothing says that a manufacturer can't make a 1000Watt supply that is unable to handle the current required on the 12V line for 3 drives - although this won't happen in practice)

The picoPSU-160-XT is rated for 160W continuous with 200W peak.  It appears to be 12v only.

The WD Red 8TB spec sheet lists the peak 12v amperage at 1.85A which is 22.2W.  Four of these drives would be 88.8W.

I would guess a J4105 with 2x 8GB RAM to pull 15W.

Three case fans maybe 15W.

If used, a PCIe SATA card 10W.

If used, a SSD cache drive 5W.

 

Total MAX of 133.8W with 4 drives and 173.2W with 6 drives (no SSD cache).

 

Looks like it should work.  What do you guys think?  Cutting it too close or perfectly in the sweet spot?

 

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29 minutes ago, ur6969 said:

What do you guys think?  Cutting it too close or perfectly in the sweet spot?

You could try it then if you have a problem we can suggest you get a different PSU😉

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4 hours ago, trurl said:

You could try it then if you have a problem we can suggest you get a different PSU😉

I mean you're not wrong but I was trying to do my research first to avoid buying two.

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Any problems with running an additional external power supply for some hard drives?

 

I was thinking of putting some hdds on a separate external power supply temporarily to determine if a problem I'm having is due to insufficient power.

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5 hours ago, javier911 said:

Any problems with running an additional external power supply for some hard drives?

 

I was thinking of putting some hdds on a separate external power supply temporarily to determine if a problem I'm having is due to insufficient power.

I do it

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7 hours ago, javier911 said:

Any problems with running an additional external power supply for some hard drives?

 

I was thinking of putting some hdds on a separate external power supply temporarily to determine if a problem I'm having is due to insufficient power.

My entire array is in an external JBOD enclosure

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Building a new ryzen 2 build next month.

 

CPU: Ryzen 3900+

Motherboard: ASROCK X570 Taichi

Drives: 9x8TB White labeled drives, 3x NVME, 4 SSD

Graphics: GTX 1080

 

Will a 600W 80+ Platinum Power supply be sufficient? I really don't know how much power these draws when full load.

 

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Guys, i'm rolling up my microservers into my SM build and will soon have around 14 drives on a Corsair HX650 psu.  Possible that this wil increase unless hard drive sizes come down in price. Problem i have is not one of wattage but rather SATA connectors of which the existing psu has only 8. I'd prefer not to split and up the usage across the two rails so am looking to buy a larger 750W psu with more connectors. Do any such single rail supplies exist anymore or are people now having to use modular units, still not recommended for unraid i see? The HX-750 has 16 sata connections but isn't single rail i believe although i admit to not reallyknowing what i'm talking about here, someone contradict me please!

Edited by superloopy1

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17 hours ago, superloopy1 said:

Guys, i'm rolling up my microservers into my SM build and will soon have around 14 drives on a Corsair HX650 psu.  Possible that this wil increase unless hard drive sizes come down in price. Problem i have is not one of wattage but rather SATA connectors of which the existing psu has only 8. I'd prefer not to split and up the usage across the two rails so am looking to buy a larger 750W psu with more connectors. Do any such single rail supplies exist anymore or are people now having to use modular units, still not recommended for unraid i see? The HX-750 has 16 sata connections but isn't single rail i believe although i admit to not reallyknowing what i'm talking about here, someone contradict me please!

Why not just buy a quality SATA power splitter? As long as it's not the molded type connectors.. The StarTech 4x ones look good.

 

SATA1.JPG.9711c6b55a16fabf0ac92eb7ab0b99b6.JPGSATA2.JPG.02d893d333f0c2143a5482f2755cb42a.JPG

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54 minutes ago, Michael_P said:

Why not just buy a quality SATA power splitter?

It is an option if used properly. The issue is the proper management of current, which can be trouble if you don't have electronics knowledge. It's easier if you can find a PSU which includes all the connectors you need, and leave the technical details for the PSU manufacturer.

 

Too many high current drives daisy chained through even a quality splitter can be trouble, the SATA power connector just isn't designed for large amounts of current. I believe the maximum 12V current through a SATA connector is 4.5 Amps, so each splitter chain is limited to that total for all drives connected.

 

A better option is the old style 4 pin connection, it can handle 11 Amps on the 12V rail, so a SATA splitter with the 4 pin connector as the source can handle many more drives safely.

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Fair point, but 3 per connector is plenty safe for modern drives (reds are like 1.8 peak)- 4 if you like to play the odds :D. It is critically important that it's a quality connector, however. Ask me how I know (hint, it involves smoke).

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