PSU 5V rail load per hdd

I’m wondering if there are some people here who can shed light on the power usage of hdd’s on the 5v rail.

I have a Corsair RM1000x PSU
It has 25A on the 5V rail, and includes 11 Sata connectors + 12 Molex for a total of 23 peripherals.

Main mainboard had 14 Sata connectors and another 8 via a Perc H310.

I’m having a bit of trouble finding solid data on the balance between 12V and 5V power usage of HDD’s
For example Exos X12 Sata, standard model.

Because I have the room and the connectors to hook up all my 21 hdd’s to a single system, but I’m worried this might overload the 5V rails of the PSU. (I’ve seen numbers of up to 1.2-1.5A per HDD as max usage on the 5V rail.)

A label on the hard drive itself should give you the max amperage for both 5v and 12v. For example here are the numbers for an old 7200 rpm 4tb seagate:

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Afaik HDDs draw more 12v than 5v because its the motor that needs 12v.

Its hard to say, because they only need full power at spinup, but i would calculate with about 1a on 5v.

By the way, if you need a bit more 5v but you have 12v headroom, you can use one of these little voltage reducers: BANKEE DC 12V 24V to 5V 15A Converter DC Voltage Reducer Regulator Step Down Buck Converter Power Supply Volt Transformer Module (12V/24V to 5V 15A): Electronics

Just wire up 12v to input and you’ll get up to 15a output at 5v! I use these on server power supplies that only supply 12v. I have a 1200w server PS that can output 100 amps at 12v, so a couple of these give me a 5v rail.

Tnx for the tip. Cant belive i never checked the label lol.

I dont really intend to splice molex together. I suppose it will work fine but well…cant be bothered. i’ll just keep it to the current 15 drives and put the rest in another enclosure.

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If it’s not printed on the label, you can usually find a PDF manual/datasheet from the manufacturer containing the exact specs.

I have 20 disks connected to a Corsair 650W and everything works fine, 14 3.5 “and 6 2.5” disks for usb.

I have a counter before the source and it marks 150W of total consumption

I had a 350W server source mounted and the disks did strange things, the funny thing is that the counter marked 80W of consumption and now when changing the source everything works ok and it marks 150W of consumption.

Interesting, guess they seldom all take full power, at least as far as farming goes.
Might try it, see what happends.

Is there a way to check the psu load per rail, does it have this report or do you have to go in with a multimeter?

Another question:

Is there something like a extension for a sata/peripherals cable?

I mean the six pin connector that you plug into the psu. I need some more length on my sata power cables to reach outside the case but all i can find are 6 pin pcie extensions and as far as I can see those have slightly different connectors than the ones used for sata power cables.

I think you want to extend the other end :slight_smile: : sata extension cable

yeah I guess that will work to tnx, but still extending the other end would be much easier

I’m sorry, I don’t have a multimeter