It sounds like you are saying that your system does not have any sort of
case fan; so, the only fans for removing the warm air from the enclosure are
those in the power supply.  If I'm understanding this correctly, your theory
that this is causing more fan noise makes sense to me.  Most power supplies
have a temperature controlled fan; so, they will run faster the hotter they
get.  Also, the motherboard may have a similar feature for providing a
temperature controlled chipset heatsink (if it has a fan) and the
processor's heatsink.  I wouldn't be surprised if this Asus motherboard has
this feature available.

You can use the Asus PC Probe utility to monitor CPU and system temperatures
and CPU fan speed.  Although it won't show the speed of your power supply
fan (unless the P/S has a fan speed connector that you you can connect to
the motherboard), you should see how the the system temperature is gradually
climbing, even with the system is at idle, and hear how the fans are getting
louder.  The CPU fan speed indicator should let you see whether this fan is
being temperature controlled as well.

As a minimum, I would look for a case with a good sized exhaust fan on the
back.  I prefer a 120 mm fan in the back because they can run more slowly
(and make less noise) while still doing an adequate job of moving air.  If
the case you are using has an openning for a back fan, simply adding on will
be helpful.  Intel has encouraged another design feature for case designers
to incorporate, which is a side port with an air guide (just a kind of tube)
that is to be located over the processor.  The idea is that this allows the
CPU fan to pull in cool air directly from the outside.  This is effective,
though not a necessity and not found on all cases.

I would recommend something like the Antec SLK1650 for a system like the one
you are assemblying, but this comes with a power supply, and you already
have one.  Their SLK 3000, which is a slightly bigger case with a door on
the front, is available from places like NewEgg in a version without a power
supply.  This might be a better fit with your needs, if you are happy with
your current 350w power supply.  They are both about the same price.

Unfortunately, many of the less expensive cases only come with a power
supply (though of dubious quality, in my opinion), and I'm not familiar
enough with some of the brands that are offering these inexpensive
enclosures without a power supply to be able to recommend one.  On the other
hand, I frequently use Antec cases and power supplies and that is why I
mention them.

I hope this is helpful.

John Sproule

----- Original Message -----
From: "Venkat Viswanathan" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, March 03, 2005 2:03 AM
Subject: [PCBUILD] fan noise


> Greetings to all list members,
> I have installed a new mobo ASUS model P4GE-MX (which has an intel 845GE
> chipset,and intel heat sink fan) and new celeron D processor 2.4 gig, a
> 350W power supply unit, in an "old" case in which earlier there was a via
> mobo, via chipset, and celeron 667 mhz processor. the case has 3 bays
> containing cdrom, cdrw, dvdrom, apart from the hdd and floppy drives and
> also has a provision for another floppy or hdd drive.
>
> The problem i notice is that after about 30/45 minutes of the system
> running there is a rather very loud whirring noise(obviously the
> fan).apart from this noise i have not noticed any operational problem even
> after 2/3 HRS of running.
>
> Since the noise bothered and worried me i removed one of the side panel
> covers and booted up.  surprisingly there is no unusal noise except for
> the gentle fan
> whirr. even after 4/5 HRS of the system running
>
> My question is, could the unusual noise (if the case is closed on all
> sides and the only ventillation is through the holes normally provided on
> the back of all cases)be due to inadequate exhaust? or could there be some
> other problem?
> is the only solution to change the case  and if so how do i decide which
> case will be ok? will be grateful for any help on the matter. wishing you
> all a very nice day.--- venkat viswanathan

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