Question Powering Multiple drives

avg9956

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Apr 7, 2019
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I am looking to power 10+ drives with my PSU. The standard 4-connector SATA power connectors are already utilized by then, so I will have to inevitably have to use a Molex to Sata Adapter.
My PSU is Seasonic SSR1000PD (1000W)
It has 5 slots for powering Peripherals/IDE/SATA/Molex

Configuration:
I use 3 slots for powering 9 drives with the SATA power Connector that comes by default with the PSU.
SATA has an ampacity of 4.5A

I wouldn't personally try connecting 4 drives in one SATA power connector, due to the guideline (NEC Code Rule) of not exceeding 80% load of any branched circuit
So 4.5*0.80 = 3.6A
Typically HDD are around 1A, so I could connect 3 HDDs safely for a total of 3A which is <3.6A.

Then the remaining 2 slots I use for Molex power connectors that comes by default with the PSU.

I have this Molex to SATA Splitter which came with the PSU.



It is of the terminal type (not molded plastic) and is said to be a reliable cable to power up drives according to this video
View: https://www.youtube.com/watch?v=TataDaUNEFc


Molex has higher ampacity than SATA (>4.5A) but it isn't standardized.

Which cable(s) should I then go for to further power up more drives? (Any recommendation would be appreciated).
 

Lutfij

Titan
Moderator
Considering that the PSU is full modular, why not fabricate your own length of wire/harness for the drives in your build? If you're not comfortable doing the wiring yourself, you can reach out to professionals like Mod-One(Titan Rig) or Ensourced customs. They should be able to make a custom harness with necessary connectors and have your wiring look neat in the process. As for your question in the thread, I'd avoid adapters since they've been known to cause more harm than good. Besides, the lower the length of cables in your build, the better.
 

jay32267

Champion
I'm not a fan of adapters or splitters but if the adapter/splitter came with a Seasonic PSU I would feel a little more comfortable.....and the fact that it's only powering one drive....the currents are low....the connection is still critical....but not as critical as something like a GPU connection.
 

avg9956

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Not sure I'm understanding but that molex to SATA splitter is also an adapter correct?

You only need to add one more drive....just use that.
Yes it is an adapter. I am looking to power more drives from that said adapter/splitter

I'm looking to add beyond 10 drives (hence 10+), so I might be looking at something like this and connect it to said adapter/splitter, if its safe?:
https://www.amazon.com/RGEEK-Splitter-HDD、SSD、Optical-Drives-Inches/dp/B096KDM9H2/ref=sr_1_1?dchild=1&keywords=SATA+splitter+amazon&qid=1625139988&sr=8-1
 

avg9956

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I'd avoid adapters since they've been known to cause more harm than good
True, hence the addage Molex to SATA lose all your data.
But I've seen some setups that are able to pull it through with using a Molex to Sata adapter, as long as they aren't the plastic molded ones they say.
This is because those types tend to have their voltage lanes become closer and closer over time, until they form an arc, which in turn bursts into flames.
The failure point mostly happens on the SATA end of the adapter.
 

jay32267

Champion
Yes it is an adapter. I am looking to power more drives from that said adapter/splitter

I'm looking to add beyond 10 drives (hence 10+), so I might be looking at something like this and connect it to said adapter/splitter, if its safe?:
https://www.amazon.com/RGEEK-Splitter-HDD、SSD、Optical-Drives-Inches/dp/B096KDM9H2/ref=sr_1_1?dchild=1&keywords=SATA+splitter+amazon&qid=1625139988&sr=8-1
Why not see if you can get more SATA power cables for your specific power supply.
 

avg9956

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I do have multiple Seasonic SSR 1000PD PSUs, just to address that sort of conundrum (I have 3 actually). I could easily get one more.

To my understanding...

As long as the pinouts are identical, then the Sata power connectors from the same exact model of power supply should be compatible with one another.

I guess we are totally avoiding Molex to Sata route

But however the problem is the cable won't reach. I plan for the Meshify 2 XL case, which has the PSU at the bottom.
I may need to buy these in order for the sata power cables to be able to reach the upper portion of the drive bay area as drives are stacked vertically further upward.
https://www.amazon.com/RGEEK-Splitter-HDD、SSD、Optical-Drives-Inches/dp/B096KDM9H2/ref=sr_1_1?dchild=1&keywords=SATA+splitter+amazon&qid=1625139988&sr=8-1

Also, isn't the SATA cable connected with the splitter I've linked still limited to the ampacity 4.5A? I still wouldn't be able to connect more drives then...
 

jay32267

Champion
I do have multiple Seasonic SSR 1000PD PSUs, just to address that sort of conundrum (I have 3 actually). I could easily get one more.

To my understanding...

As long as the pinouts are identical, then the Sata power connectors from the same exact model of power supply should be compatible with one another.

I guess we are totally avoiding Molex to Sata route

But however the problem is the cable won't reach. I plan for the Meshify 2 XL case, which has the PSU at the bottom.
I may need to buy these in order for the sata power cables to be able to reach the upper portion of the drive bay area as drives are stacked vertically further upward.
https://www.amazon.com/RGEEK-Splitter-HDD、SSD、Optical-Drives-Inches/dp/B096KDM9H2/ref=sr_1_1?dchild=1&keywords=SATA+splitter+amazon&qid=1625139988&sr=8-1
I was just trying to avoid an added plug/socket connection.
If you are going to wind up with one anyway...you might as well just go with the molex to SATA adapter.
 

avg9956

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you might as well just go with the molex to SATA adapter
Yes sadly, even I don't personally like it too, but this is the only recourse for me to connect more drives as Molex has higher ampacity than SATA.

Just gotta figure out what the ampacity of my Molex connector is, but its definitely >4.5A
It maybe around 8-11A.
 

jay32267

Champion
Yes sadly, even I don't personally like it too, but this is the only recourse for me to connect more drives as Molex has higher ampacity than SATA.

Just gotta figure out what the ampacity of my Molex connector is, but its definitely >4.5A
It maybe around 8-11A.
I recall looking this up...and it's more than 3 or 4 drives. I think it might be 12 amps.
 

Ralston18

Titan
Moderator
Just a quick question about the bigger picture.

What is driving the requirement to have 10+ drives?

Although the power issues are likely addressable in a number of ways I would be (and I am) concerned about the proverbial "all eggs in one basket".

It just seems that all could go wrong very quickly.....
 

avg9956

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I am getting into Chia farming :)
Trying not to have to use a second PSU with my planned case, otherwise I can't imagine having to take off the rear side panel just to get a 2nd PSU, and then sneak in something like this to make the PSUs start together and also be limited with SATA connectors only...
I'm facing a dilemma similar as to how home server builders want their setups to only have one PSU, inside their enclosure.
https://www.reddit.com/r/HomeServer/comments/f0td2f View: https://www.reddit.com/r/HomeServer/comments/f0td2f/16_hard_drives_powered_off_single_psu/
It can be done, but they used Molex to Sata for it. A necessary evil, a means to an end.
 
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avg9956

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I asked someone for advice, and this was what they recommended to me on how to go about this.
I should only limit "One molex line" to a max of 2x Molex to 4 SATA Connectors.



Which if true and everything checks out (even the amperage calculations below)
Lets assume HDD is typically 1A each.
With 2x Molex to 4 SATA Connectors, I can connect up to 8 drives (8A).
But molex has 11A ampacity or so...
So there's 3A allowance for drive spin-up state, where there's a very momentary spike of power needed to start the device up. I think that's more than enough to cover the 8 drives' spin-up state when connected...

From my own experience of using regular PC power supplies over the years... Yeah, stick with the molex connectors as possible, but if you can plug some of your drives directly into those SATA connectors
(and they are of good quality) then that will help. The biggest issue I've had, and it took me awhile to figure it out, is that you won't have your entire 550W supplied to every one of the output connectors.
Rather, the power supply output is split up between those connectors, so you need to pay attention to how you connect everything to keep the load evenly spread across as many of the output cables as possible.

For instance, if you have four molex connectors coming out, you want to try and evenly split your drives between those connectors. If you try to use a series of splitters and connect all 16 drives through a single molex,
you WILL see brownouts which will spell disaster for a raid5 type setup.
https://www.reddit.com/r/HomeServer/comments/f0td2f View: https://www.reddit.com/r/HomeServer/comments/f0td2f/16_hard_drives_powered_off_single_psu/


If these are all true, then it should check out.
 

faalin

Judicious
I am looking to power 10+ drives with my PSU. The standard 4-connector SATA power connectors are already utilized by then, so I will have to inevitably have to use a Molex to Sata Adapter.
My PSU is Seasonic SSR1000PD (1000W)
It has 5 slots for powering Peripherals/IDE/SATA/Molex

Configuration:
I use 3 slots for powering 9 drives with the SATA power Connector that comes by default with the PSU.
SATA has an ampacity of 4.5A

I wouldn't personally try connecting 4 drives in one SATA power connector, due to the guideline (NEC Code Rule) of not exceeding 80% load of any branched circuit
So 4.5*0.80 = 3.6A
Typically HDD are around 1A, so I could connect 3 HDDs safely for a total of 3A which is <3.6A.


Here are 4 drives I just happen to have laying in front of me

Seagate Exos enterprise 2TB SAS 2.5" +5v .6A +12v .3A
Seagate Constellation ES.2 SED 3TB SATA 3.5" +5v .58A +12v .53A
WD WD800BB 80GB IDE 3.5" +5v .35A +12v .5A
No name SSD out of a dell 256GB +5v 1.5A

Somewhere on the label it will tell you how many amps each drive will take. Theres no need to try and guess how many amps they will use, it tells you.
 

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