How much power does a hard drive use?

  • Thread starter Thread starter half_pint
  • Start date Start date
half_pint said:
I guess you might need some clever (and expensive) storage
oscilloscope?
I suppose you could program a clever (expensive) meter to detect
a transient voltage drop? I don't know as I am unfamiliar with 'em.
What do you think of my idea of soldering a resistor across
the power rails to drain off some power?
It would certainlty be cheap (which is what attracts me!!).
I might end up frying my computer permanently though.(no so cheap - lol).
Click to expand...

If you want to try that idea, a 12 V auto tail lamp works well. A 1073
lamp draws 1.8 A at 12 V and a 1156 will draw 2.1 A. this is ~22 W or
~25 W. If you can't find a suitable socket, you can easily solder leads
to them. You might even see a change in light output, but I'd not count
on it. Any way they're cheaper and easier to find than a suitable
valued resistor that will take 30 W. The start-up current for a typical
hard drive is ~2.5 A and running current is ~ 1 A.
I also believe it is the capacitor in PSU's which fail over time, maybe
I can get some cheap some where?
Click to expand...

Probably not worth the trouble. In addition to the input capacitors there
are a half dozen or so low ESR units in the output circuits.
My 90W PSU dont seem a lot though, barely a light bulb!
Click to expand...

Is it in the same size enclosure as a standard ATX supply? If not a
repair might make sense--otherwise probably not worth trying. HSC
electronic has a 200W standard ATX unit for $12.50 (www.halted.com).
Don't tell w_tom! ;)

Virg Wall
 
Yes it would be nice to have one of those but unfortunately I don't.
Maybe I will buy one if they are fairly cheap, it would come
in handy anyway.
Actually I am sure my brother(s) uses one for work so maybe I
can borrow one.
Or maybe I get one on ebay?
Would it show a brief voltage drop?
A drop of a few milliseconds might cause the problem.
Click to expand...


To what end would you test?
Is this a proprietary, unreplacable (or great expense to) unit, or just a
standard ATX or mATX, meaning a suitable replacement could be found for
under $30 USD?

Then I have the prob of what caused the drop, general
overload or faulty memory or a combination of both!!
Click to expand...

If PS shuts off with full system you can pull parts and retry system... it
won't POST with some required items in it, but things like memory, with
that pulled the power supply should continue running, not shut off, even
if the system doesn't post. With that method you could isolate faulty
components except the motherboard.
Actually I have just been thinking ( which is sometimes a dangerous thing
to do for me!!)

I could (if I had a soldering iron and resistor) solder a resistor across
the
power supply to draw off some power. If I drew off say 10-20% of the
power and the booting problem manifest itself on a regular basis that
mighr prove something (or not!).
I am not sure what the PS voltage is though.
Power =V(squared)/R so 10% of my 90W = 9W=VV/R
if V=12 then R=144/9 ~= 150 ohms.
If V=5 R~=2.5 ohms.

I could also permantly damage my computer in the process - lol !!
Click to expand...

There should be no reason to add resistors or other loads to "draw off
power". The power supply is marginal already, adding more load isn't
likely to help since it already had load on major (3, 5, 12V) rails so all
you'd be doing is further descresing the odds the the unit has enough
capacity to power the system.

Could I set up such a meter to record or beeb if the voltage dropped
below a certain level?

Anyway my computer has behaved it self for the last 3-4 hours.
It usually decides to freeze when I have spent 1/2 an hour typing
a reply in OE so perhaps it realy does just hate me!!
Otherwise the problem is a fairly minor irritant.
Click to expand...

You've ruled out overheating and poor contacts (pulling, inspecting, and
reinstalling cards, CPU, memory, cables, etc)?

I used to have to reboot a few times a day anyway due to software
probs (exceptions, out of memory etc..), maybe some of these were
due to the PS? Who knows? Not me anyway!!!!

regards half_pint.
Click to expand...

90W power supply is going to be spec'd to support only original
components, little if anything else. If the system has been upgrading
beyond original configuration you like have exceeded the unit's capacity.

However the first step is as others have mentioned, the simple voltage
readings on all rails with a multimeter.
 
In the manual it says the PS is ATX 90W.

I comes with one hard drive (obviously) and a cdrom with a spare
5.25 inch drive bay. So it is only designed for 3 drives of any type.
I could well be pushing it a bit with my 4.
It has onboard sound and video though.

I just looked in a PC mag and the smallest I could find was 300W!!
so my 90W does seem inadaquate not even a 1/3 of the minimum available!!
I would guess extra memory uses more power too.

The power supply theory does fit in pretty welll with the symptoms.

If I can run memtest OK for 10 hours I can hardly blame the memory.
Certaintly not enough to claim a refund.

Maybe switching the speakers off will help - lol.
Click to expand...

Move one of those hard drives to an external
USB2/Firewire enclosure.

Or get a bigger power supply.

Or use 5400rpm drives or laptop drives.
 
Toshi1873 said:
Move one of those hard drives to an external
USB2/Firewire enclosure.

Or get a bigger power supply.

Or use 5400rpm drives or laptop drives.
Click to expand...

They are 5400 drives.
A bigger PSU is probably in order.
The capacitors in PSU's have a lifetime expectancy and are
one of the few electrical components which 'wear out' I am told.

Just putting a bigger capacitor(s?) in the PSU might do the job,
nut I am not sure if it is as simple as that.

I will have a look on ebay.
 
VWWall said:
lol).

If you want to try that idea, a 12 V auto tail lamp works well. A 1073
lamp draws 1.8 A at 12 V and a 1156 will draw 2.1 A. this is ~22 W or
~25 W. If you can't find a suitable socket, you can easily solder leads
to them. You might even see a change in light output, but I'd not count
on it. Any way they're cheaper and easier to find than a suitable
valued resistor that will take 30 W. The start-up current for a typical
hard drive is ~2.5 A and running current is ~ 1 A.
Click to expand...

Sounds like a good idea after all bulbs are basically just resistors.
I am sure I have plenty of bulbs around the place.

I am not sure what the power 'rail' levels in a PC are though,
I think there are several? The power connector has 4 wires on
it 12, 5, 3.5, 0?
I have no idea, would the red one be 12V or 5? Probably 5 I imagine.
Just had a look inside, it says +5 OVP on the PSU case
Probably not worth the trouble. In addition to the input capacitors there
are a half dozen or so low ESR units in the output circuits.


Is it in the same size enclosure as a standard ATX supply?
Click to expand...

I think so yes it says ATX on the lable anyway.
 
I will put a meter on my shopping list.
Along with a soldering iron and a few other useful things
 
CBFalconer said:
Here is where an old fashioned analog meter with a needle is
better. You are likely to get some indication of that hole. With
a DVM you probably won't, depends on the sampling rate and
mechanism etc.
Click to expand...

The problem is the problem is too in frequent, it doesn't even
fail every day. The probably might only manifest it self for one
split second in 24 hours so the chances of me catching ot are
approximately zero.
 
kony said:
To what end would you test?
Is this a proprietary, unreplacable (or great expense to) unit, or just a
standard ATX or mATX, meaning a suitable replacement could be found for
under $30 USD?
Click to expand...

From the manual:-
Chassis Mirco Tower ATX
Puer Supply ATX 90W
If PS shuts off with full system you can pull parts and retry system... it
won't POST with some required items in it, but things like memory, with
that pulled the power supply should continue running, not shut off, even
if the system doesn't post. With that method you could isolate faulty
components except the motherboard.
Click to expand...


Problem is the problem is intermittant, system has ran perfectly for
the past 24 hours, 10 of which was running memtest.
It's running like a dream at the moment, as if it would never
fail again (famous last words!).
There should be no reason to add resistors or other loads to "draw off
power". The power supply is marginal already, adding more load isn't
likely to help since it already had load on major (3, 5, 12V) rails so all
you'd be doing is further descresing the odds the the unit has enough
capacity to power the system.
Click to expand...


That was the whole idea, to make an infrequent problem manifest itself
on a regular basis, so it can be cured for certain.
You've ruled out overheating and poor contacts (pulling, inspecting, and
reinstalling cards, CPU, memory, cables, etc)?
Click to expand...

The infrequency of the problem make this difficult as I have
had several days of faultless running recently.


For instance I put my old memory back in and after 3 days
of faultless running I assumed it was the new memory -
that is untill I put the new memory back in and it also
ran faultless for three days!!!!

In total thats a week without any fault whatsoever!
90W power supply is going to be spec'd to support only original
components, little if anything else. If the system has been upgrading
beyond original configuration you like have exceeded the unit's capacity.
Click to expand...

I am probably right on the line, or just a tiny bit over.
However the first step is as others have mentioned, the simple voltage
readings on all rails with a multimeter.
Click to expand...

As soon as I can get to the shops!
 
From the manual:-
Chassis Mirco Tower ATX
Puer Supply ATX 90W
Click to expand...

.... but that doesn't tell us if it's a standard ATX or mATX size or not.
Google search mATX and ATX power supply dimensions so you can see those
and measure it... there's no point to going to a lot of trouble if it's
standard. A standard mATX 185-200W unit is about $25 USD.


Problem is the problem is intermittant, system has ran perfectly for
the past 24 hours, 10 of which was running memtest.
It's running like a dream at the moment, as if it would never
fail again (famous last words!).
Click to expand...

Try to find any possible pattern. Perhaps temp (not necessarily system
temp but room temp). Caps work better when warmer (but then wear out
faster too).

That was the whole idea, to make an infrequent problem manifest itself
on a regular basis, so it can be cured for certain.
Click to expand...

But it might only happen intermittently still, only barely more often
which may not be conclusive, or your additional load might present a 2nd
problem, making further diagnosis even more difficult if you drew a false
conclusion based on results of adding the load.

For instance I put my old memory back in and after 3 days
of faultless running I assumed it was the new memory -
that is untill I put the new memory back in and it also
ran faultless for three days!!!!

In total thats a week without any fault whatsoever!
Click to expand...

Is it possible you simply have poor AC power? You might note if there's
anything else running at same time as fault, particularly on same circuit.

I am probably right on the line, or just a tiny bit over.
Click to expand...

Even if the unit originally supported the comonents attached, IMHO that's
too little margin, ideally the power supply shouldn't be operating near
it's limit in the first place but the manufacturer cheaped out only
providing 90W unit.
 
A power supply that cannot provide sufficient power to load
may only cause a computer crash once a week BUT will show the
problem on a meter every minute of that week.
 
They are 5400 drives.
A bigger PSU is probably in order.
The capacitors in PSU's have a lifetime expectancy and are
one of the few electrical components which 'wear out' I am told.

Just putting a bigger capacitor(s?) in the PSU might do the job,
nut I am not sure if it is as simple as that.
Click to expand...

Buying a new power-supply is a lot cheaper then medical
bills (even with co-pays) or frying other components
because you got a cold solder joint. Quality P/S is
only $50 or so (usually less).
 
... but that doesn't tell us if it's a standard ATX or mATX size or not.
Google search mATX and ATX power supply dimensions so you can see those
and measure it... there's no point to going to a lot of trouble if it's
standard. A standard mATX 185-200W unit is about $25 USD.
Click to expand...

Not to mention the problem that certain vendors like to
use non-standard pin-outs on their motherboard power-
supply connectors. (Dell is the culprit that I've heard
this assigned to.)
Is it possible you simply have poor AC power? You might note if there's
anything else running at same time as fault, particularly on same circuit.
Click to expand...

A good UPS with voltage regulation might be useful.
(e.g. APCs BackUPS-Pro series, IIRC, has voltage
regulation). Usually only needed if you live in cities
with brown-out conditions or you have a heavy piece of
equipment (AC unit, fridge, electric stove maybe) on the
same circuit.
Even if the unit originally supported the comonents attached, IMHO that's
too little margin, ideally the power supply shouldn't be operating near
it's limit in the first place but the manufacturer cheaped out only
providing 90W unit.
Click to expand...

Agreed, move the extra devices out of the case to reduce
the load on the main P/S. External USB/firewire
enclosures are cheap, and have the bonus of making gear
portable.
 
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