Ask HN: Can I use another PSU to power a HDD?

#1

Post by Spock » Wed, Mar 14, 2012, 9:35 AM UTC

I have 2 PSUs, one is an IDE Molex, the other is SATA connectors. The SATA PSU is tempermental, so I use the molex one as I have all IDE devices.

I need attach a few hard drives from another machine which are SATA and my question is, while the computer is powered from molex, can I also plug my SATA PSU into the hard drive, with a SATA cable to my motherboard, and power it that way? Sorry if it doesn't make much sense, I'm rushing and a bit stressed (kids)

Re: Ask HN: Can I use another PSU to power a HDD?

#2

Post by dirkdeman » Wed, Mar 14, 2012, 9:51 AM UTC

I guess it could be done, but is our PSU beefy enough to power a couple of HDD's?

Re: Ask HN: Can I use another PSU to power a HDD?

#3

Post by Spock » Wed, Mar 14, 2012, 10:09 AM UTC

dirkdeman wrote: post #2

I guess it could be done, but is our PSU beefy enough to power a couple of HDD's?

800W PSUs. Would it actually power the drive without being directly into the mobo first?

Re: Ask HN: Can I use another PSU to power a HDD?

#4

Post by brk » Wed, Mar 14, 2012, 10:27 AM UTC

Yes, you can.

Ideally they'll share the same chassis ground (connect the metal cases together), but it's not strictly necessary (based on personal experience).

Re: Ask HN: Can I use another PSU to power a HDD?

#5

Post by glimcat » Wed, Mar 14, 2012, 10:53 AM UTC

Yes, but you shouldn't. Also, adapters are a couple bucks on Monoprice.

Also, a "tempermental" PSU may need to be replaced before it does destructive testing of the components connected to it.

Re: Ask HN: Can I use another PSU to power a HDD?

#6

Post by Spock » Wed, Mar 14, 2012, 11:31 AM UTC

glimcat wrote: post #5

Yes, but you shouldn't. Also, adapters are a couple bucks on Monoprice. Also, a "tempermental" PSU may need to be replaced before it does destructive testing of the components connected to it.

I'm in the UK, and it's something that needs to be done today, I don't have time to order adapters. Also, like I said, I use the molex PSU, which is fine. The SATA is tempermental, hence why I'm not using it.

Re: Ask HN: Can I use another PSU to power a HDD?

#7

Post by nik_0_0 » Wed, Mar 14, 2012, 9:02 PM UTC

Spock wrote: post #3

dirkdeman wrote: post #2

I guess it could be done, but is our PSU beefy enough to power a couple of HDD's?

800W PSUs. Would it actually power the drive without being directly into the mobo first?

You wouldn't be able to plug in the 24pin ATX connector to the mobo, which is how the PSU gets the signal to turn on. It is a simple bridge of two ports (google for 24pin atx bridge on), which will leave your PSU on all the time, if it has a switch on the back that will make for easy on/off switching.

However, as said above, adapters are much simpler :)