power supply

Is it okay to use one power supply for the motherboard and a different
power supply for the hard drive on one PC?

Thanks.

bob@coolgroups.com wrote:
> Is it okay to use one power supply for the motherboard and a different
> power supply for the hard drive on one PC?
>
> Thanks.

Yes, it can be done, and sometimes IS done. But.... it's not something
you need to do. I can't see any justification for this in an ordinary
pc.

On 9 Sep 2006 20:28:39 -0700, bob@coolgroups.com wrote:

>Is it okay to use one power supply for the motherboard and a different
>power supply for the hard drive on one PC?
>
>Thanks.

Yes but they should have a common ground (DC side, not
necessarily AC).

One hard drive is not much load, a couple amps at power-on
and/or spin-up, but otherwise typically about 0.5A per 5V &
12V rail or less... that is not much, if your main PSU
doesn't have this much reserve it might be better to
consider a higher capacity main PSU.

On the other hand, if you had quite a few drives it begins
to make more sense, though depending on how the 2nd supply
is controlled, you might want or need to devise how that 2nd
supply will turn on with the majority of the first one...
which can vary depending on exactly what this 2nd supply is.

On 9 Sep 2006 20:28:39 -0700, bob@coolgroups.com wrote:

>Is it okay to use one power supply for the motherboard and a different
>power supply for the hard drive on one PC?
>
>Thanks.

Sure but it's a lot of trouble to go through unless you have a really
compelling reason to do it. A few people have done that for some
fancy case mods where the extra fans, neon tubes, video displays,
animatronic fuzzy dice, etc drew too much current for even a single
high end PSU. What you're proposing probably won't need you to go to
such extremes.

If it's just that you've run out of connectors, go to your local
computer shop and buy either a Molex Y-cable, or a Molex Octopus
cable. Locally, it's something like $6 for the Y-cable, and $25 for
the Octopus cable (splits off a single Molex connector into 6 to 8
connectors). Your local pricing will vary.

If it's that you think your PSU isn't powerful enough for what you've
got and that one hard drive will push it over the edge, you'd be much
better served by replacing your existing PSU with a beefier one. Saves
having to figure out how to mount the second one, as most cases don't
have a cage for more than one.
---------------------------------------------
Thanks.


MCheu