Hi,

I'm buying a new power supply for my system, but all the other parts are
staying the same.

If I buy a 400w power supply will it run hotter and use more electricity
than a 300w power supply when powering the same components?


Thank you,

-Kerry

Kerry wrote:
> Hi,
>
> I'm buying a new power supply for my system, but all the other parts are
> staying the same.
>
> If I buy a 400w power supply will it run hotter and use more electricity
> than a 300w power supply when powering the same components?

It will produce about the same amount of waste heat, unless its
efficiency is very different. Unless I am wrong, there is not a huge
difference in efficiencies of different PSUs.

"Kerry" <(E-Mail Removed)> wrote in message
news:UwBWb.74982$(E-Mail Removed)...
> Hi,
>
> I'm buying a new power supply for my system, but all the other parts are
> staying the same.
>
> If I buy a 400w power supply will it run hotter and use more electricity
> than a 300w power supply when powering the same components?
>
>

Since "all the other parts are staying the same" the 400 Watt P/S will
supply the same amount of power that your 300 Watt P/S was sending to your
system. Just because a P/S is "rated" at 400 Watts or whatever its rating
does not mean it supplies a constant 400 Watts. It supplies what a system
needs up to its capacity. If the P/S's capacity is exceeded it will
hopefully shut down gracefully without damaging itself or any supplied
components.


If the new P/S has more efficient heatsinks than your older P/S it might
actually run somewhat cooler than the old one for the *same* load.



--
callsignviper


The truth is out there. You just have to look in the right places and ask
the right questions.

A reply to Kerry who did not appear in my newsgroup:
Quite possible that a 300 watt supply could also provide
more power than a 400 watt supply for numerous reasons. Power
consumption would be about same. But a 400 watt supply may,
functionally, not provide as much power. Too many look a
price and total wattage - and therefore end up with an
inferior supply. For example, look at the wattage that
responsible engineers put inside properly designed systems.
Something on the order of 200 watts. However when power
supplies are mismarked, overhyped, missing essential
components, etc, then cloners hype the "Home Improvement"
concept of more power.

Suggest reviewing a previous discussion in
alt.comp.hardware.pc-homebuilt entitled "GOOD power supply
for under $40?" starting 20 Jan 2004 or
http://tinyurl.com/3h6wa

Some have emotional attachments to myths which is why watts
and price rather then specifications and value are promoted.
Most important, does your new supply claim to include those
all so important functions that were even defacto standard 30
years ago - and so often missing in many 'discount' power
supplies with more watts.


Matt wrote:
> Kerry wrote:
>> I'm buying a new power supply for my system, but all the other
>> parts are staying the same.
>>
>> If I buy a 400w power supply will it run hotter and use more
>> electricity than a 300w power supply when powering the same
>> components?
>
> It will produce about the same amount of waste heat, unless its
> efficiency is very different. Unless I am wrong, there is not a huge
> difference in efficiencies of different PSUs.

Kerry wrote:

> If I buy a 400w power supply will it run hotter and use more electricity
> than a 300w power supply when powering the same components?

No.

> If I buy a 400w power supply will it run hotter and use more electricity
> than a 300w power supply when powering the same components?
>
<snipped>
>
> If the new P/S has more efficient heatsinks than your older P/S it might
> actually run somewhat cooler than the old one for the *same* load.
>

Power is Power. If you have two supplies of equal efficiency powering a
given load they will both be generating the same amount of heat. It does
not matter that one supply has 400W capability and the other 300W , so long
as the load does not exceed 300W (or none of the individual power rails
exceed its individual power rating).

If you have a more efficient heat sink on a given component, that component
will indeed run cooler assuming the air flow is the same...but it will still
be dissipating the same amount of power (igoring the miniscule changes in
conductance due to temp of course).


(*>

"Kerry" <(E-Mail Removed)> wrote in message
news:UwBWb.74982$(E-Mail Removed)...
> Hi,
>
> I'm buying a new power supply for my system, but all the other parts are
> staying the same.
>
> If I buy a 400w power supply will it run hotter and use more electricity
> than a 300w power supply when powering the same components?

No.

"jeffc" <(E-Mail Removed)> writes:
>
> "Kerry" <(E-Mail Removed)> wrote in message
> news:UwBWb.74982$(E-Mail Removed)...
> > Hi,
> >
> > I'm buying a new power supply for my system, but all the other parts are
> > staying the same.
> >
> > If I buy a 400w power supply will it run hotter and use more electricity
> > than a 300w power supply when powering the same components?
>
> No.

This is only true if you assume the new power supply has the same, or
better, efficiency.

The heat generated is a function of the power being drawn and the
efficiency of the power supply. A less efficient power supply will
generate more heat for the same amount of power being drawn by the
PC's components.

This has nothing to do with the maximum rating (in watts) of the
supply.

Jeff
--
Remove "no" and "spam" from email address to reply.
If it says "This is not spam!", it's surely a lie.

w_tom wrote:
> A reply to Kerry who did not appear in my newsgroup:
> Quite possible that a 300 watt supply could also provide
> more power than a 400 watt supply for numerous reasons.

A 330w supply will not supply any more power than a 400w supply when
connected to the same system.

<Snip adolescent lecture on issue that wasn't raised by OP>

Martin


---
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Checked by AVG anti-virus system (http://www.grisoft.com).
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"jeff findley" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> "jeffc" <(E-Mail Removed)> writes:
> >
> > "Kerry" <(E-Mail Removed)> wrote in message
> > news:UwBWb.74982$(E-Mail Removed)...
> > > Hi,
> > >
> > > I'm buying a new power supply for my system, but all the other parts
are
> > > staying the same.
> > >
> > > If I buy a 400w power supply will it run hotter and use more
electricity
> > > than a 300w power supply when powering the same components?
> >
> > No.
>
> This is only true if you assume the new power supply has the same, or
> better, efficiency.

I assumed "all else being equal" went without saying :-)