Question Power for Many HDD advice needed

Jan 23, 2020
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I have a custom build PC running Windows 10 acting as a headless server built in a 19inch Rack Box

Its an MSI Z390 Pro with a i5-9400F, 16gb corsair memory, 700W power supply - the system is fine - no problems with the OS.

In the motherboard is an Nvidia card, along with pcie raiser/splitters and 8 port SATA expansion cards and 5 Gigabit LAn ports running teamed.

Currently there are 20 SATA 3 Connectors, but not more than 7 SATA drives at present at the moment. I aim to put in 20 HDDS or maybe even more if i can power them.

It is using Microsoft Storage spaces to add space as 1 viewable drive (many drives with redundancy acting as 1 drive)

My problem is this:

My power supply doesnt fit to the Removeable caddies connectors as they are molex, but my power supply has 1 cable with 3 molex and another with 6 sata power connectors. I have on order some sata to molex convertors, but the havent arrived yet.

IF i add another drive I have a SERIOUS problem, instead of the power drain cutting off the power supply, the molex cables spark and crackle, then burst into flames and kill the hdd (thankfully nothing else although this is breaking me ...), if the machine were unattended it could be disaterous!. I turn off the Power supply and kill the flames, This is NOT acceptable at all! I am no expert but I am assuming the power drain is too much and a current surge is happening with the HDD tries to spin up.

So currently the 7 HDDs (all spin type not SSD) are powered with splitters from the MOLEX cable, the sata cable is not currently in use. This is probably at its limit or mioght be over it. I am going to try and use the othe PSU cable when the adaptors arrive.

So What Can I do?, I have other power supples handy and have been reading how to use them, but someone here might have more safe and better advice on here. If it jump (connect) on the 24 pin connector the green and black the PSU will power up. So I can do that to gain another power / current source, but is it safe to do this with the sata data cables connected from a motherboard on another power source?

Would I need to use more power supplies to power 20+ drives. ... I dont know myself but think its likely...

Anxiously awaiting some decent advice ......
 

Eximo

Titan
Herald
Certainly larger power supplies with modular connectors. You could order or make custom cabling that can handle the current.

Yes, you can use multiple PSUs. You need to tie the chassis grounds together for safety, and splice in (There are people that make dual PSU adapters, for just such occasions, more so since the whole crypto mining craze) the standby power pins and several common pins together so the power supplies share a common.

Again with modular cables, you can create the connections you need for twenty drives with substantial cables.

Key to all of this is making sure the voltages you are pulling have sufficient amps for the devices you plug in. Each drive should have its power needs written on them, add them up and see what it comes to. Compare that to the PSU label. If you are exceeding anything, need a larger, or different supply.

Molex to SATA adapters are usually cheaply made and are not to be trusted. I don't know if anyone makes good ones. Probably the most common failure you see from melted computers. Basically people putting newer hard drives into older PCs.
 
I was about to say that China adapters are crap, they use like 0,75mm2 or 18AWG rarely copper or copper plated but mostly aluminium.
They are very soft.

As for me , with some will and sacrifice you may build your own sata splitters from dead PSU cause the sata connectors have their own "Legs" which crimple the cable as you push it in.
Just beware of the not putting too many on one single line.
 
Hard drives typically only draw around 5-10 watts each when in use, which for 20 drives would only be around 100-200 watts from the PSU combined. However, when they are first spinning up, they may draw as much as 30 watts each as the drive gets up to speed. You need to enable staggered spin up so that the drives don't all try to spin up at the same time, and instead go one after another.
 
Jan 23, 2020
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Thanks for the advice guys.

As for loosing data, I don't want to loose any. I don't have the budget to build the perfect option, otherwise I would just buy it. .

Storage space has 3 way mirroring so that's not the issue here, the power and cables are though.

I didn't know about the dual power supply sync cable. Looking at them they are just joining the green and black cables so that power on switches them both on at the same time.

I will look at building my own molex cables, it would definitely be safer. The sata to molex is a weird one because the drive caddies are sata inside. But molex on the back. So it would be sata to molex and back to sata...... Weird.


Thanks for the help guys
 

USAFRet

Titan
Moderator
Mar 16, 2013
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"20 drives"
What specific make/model/size are these?

Any type of merger/RAID really really needs a dedicated RAID controller.
Storage Spaces is a poor substitute.

And "loosing data " is always a possibility. This is what backups are for.
 

Rogue Leader

It's a trap!
Moderator
IF i add another drive I have a SERIOUS problem, instead of the power drain cutting off the power supply, the molex cables spark and crackle, then burst into flames and kill the hdd (thankfully nothing else although this is breaking me ...), if the machine were unattended it could be disaterous!. I turn off the Power supply and kill the flames, This is NOT acceptable at all! I am no expert but I am assuming the power drain is too much and a current surge is happening with the HDD tries to spin up.
Wait did this actually happen or you are speculating.

Voltage matters less in this case than amps. SATA cables have a max of about 4.5 amps, in theory. HDD's pull about 0.5a normal, however on startup that could be 1a or more, so 4 drives on a SATA cable starting up could be a real problem. So Splitters are a bad choice. Molex connectors are rated higher but once you stick that adapter in there all bets are off, those things are not safe.

And yeah Storage Spaces, for this many drives? RISKY

How much total storage are we talking here? Where did you get the idea to do this? And what does this system do, just provide storage? Media Server?
 
Jan 23, 2020
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I think the molex splitters are the problem.

Yeah the fire actually happened, twice... I've had computers since forever, the mid 80s ish dx25 was my first upgrade then to a 33mhz lol.

I have a lot of data, old and new. The new system is to replace quite a few nas systems in the hope of reducing overall power used.

It will do all sorts from Web server (internal and external), a small media server for my VHS and dvds and my vinyl music, it'll also be my programming repo. As well as my family cloud device. So yeah needs quite a bit of storage.


It's all good except for the power issue
 

popatim

Titan
Moderator
...Storage space has 3 way mirroring so that's not the issue here, the power and cables are though.
My experience with Storage spaces mirrors is not going very well. I have two 3TB drives in a Storage Spaces mirror and at least once a month they lose sync and need to rebuild, killing all performance during the process. I can't image how horrible with would be with a 3 way mirror. These same drives have no issue working perfectly fine in a mirror on my raid card.

If you really need a mirror, make it a 2 way and then use that 3rd set of drives as an off-line backup so at least if the server goes down (or up in flames) you still have your data. Having 2 offline backups , where one of them isn't kept in the house is even better. This way if something really bad happens you can rescue your data from someplace like a family members basement. Mine is in my sisters basement and I figure if something takes out both our houses, I'm probably dead and won't care. LoL

As for staggered spinup of the HDD's, there's 2 methods and both require compatible hardware support.
1: Powerup in Standby (PUIS) needs compatible HDD's and Storage Controller
2: SSU Signaling method needs Storage Controller and HDD backplane support.

Without going to server grade hardware, you're not likely to achieve this.
Some HDD's can be set to PUIS using HDParm but then you still need a supporting Controller.
 
Jan 23, 2020
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I currently have 7 drives, different makes and sizes from 3tb to 8tb and have not had a problem with storage spaces yet like you suggest. The only issue I get is if I add a pre used drive and format it in disk management it gives error 32 cannot add drive, until I reboot then it does add it without the error.

I don't know if its anything to do with it but my drives don't run from the motherboard sata, but run off expansion sata cards.
 
Jan 23, 2020
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I took apart the molex splitters and am actually horrified by how crap they are.

The cable quality is probably only good enough for 1 drive, not 3.. albeit they are actually copper cables. Each cable looks good from the outside, quite thick, but thats nearly all sheath. There are 5 stands of very thin copper inside. If it were solid copper (1 strand) it'd probably be good. The had behaved like a fuse wired blowing and setting fire to the sheath. The originals sheaths were flammable ffs!
It gets even worse, the connection to the molex is a simple crimp, no solder!. On a couple of these the cables actually are crimped without stripping back to the copper too! so next to no copper to molex pin touching.

I need to use these at present, so I have made some up myself from an old motorcycle harness in my shed and soldered the pins. They are the wrong colour coded wires but pin to pin are correct - so thats fine. There are about 20 strands of copper in these and each strand is probably double the thickness of the original molex wires.

I will eventually go down the route of syncing two or more power supplies with the power cycle switch and add in power like that along with replacing all the cables from inside the PSU's for higher quality ones and soldered joints.


Thanks to all for your advice, at least I am now more knoledgeable than before! - and at a lot less risk of fire
 
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