sucks or blows, which is better?

R

ric

Gianmaria said:
I read all the replies you got and it seems that all agree with the
standard layout of the tower case: PSU on the top blowing out and low
front fan sucking in.
I do not agree on the front fan; it is rather useless especially if
the PSU has 2 fans. The airflow created by PSU is excellent and is
enough to suck air from the lower ventilation holes.
Click to expand...

The front fan is useful for two reasons:

1) It decreases the static pressure seen by the rear (or PSU) fan, allowing
it to operate more efficiently (closer to its published zero static
pressure CFM.)
2) It allows for directing of much of the incoming air through a filtered
inlet, keeping the inside of the case more dust free, and keeping dust
away from HDs, CD drives, and DVD drives.
 
T

ToolPackinMama

Al said:
That's a great temperature, but is it your regular running
temperature, or your temperature under full load?
Click to expand...

The one I mentioned before is not *my* personal computer. The person I
built it for uses it for web browsing and "Bejewelled". I don't really
think it's ever going to see any hard use. :)

My personal computer has PS fans, CPU fan, an extra case fan to exhaust
air, and there is a little cooling fan on the ATI A-I-W 9600 vid card,
as well. My cpu temp stays under 100 f. The only games I play are
Morrowind and The Sims.
 
T

ToolPackinMama

ToolPackinMama said:
I just built a Athlon XP system and the only fans in it are the PS fans
and the CPU fan. The CPU temp stays under 100 f. and the sys is nice
and quiet.
Click to expand...

Holy cow, talk about a brain fart. That was incorrect what I said
before. The _system temp_ stays well under 100 f. The CPU temp
averages between 40-50 c. That's with the stock AMD heatsink/fan, and
no overclocking.

Right now my PC (AMD Athlon XP 2200+ CPU, a Epox 8RDA+ motherboard
(NFORCE2 chipset), 120 G. 7200 RPM Seagate ATA 100 HD (dual-booting
WinXP Pro and SuSE Linux 9.0), 512 MB of 2700 DDR system RAM, ATI 9600
Radeon All-in-Wonder AGP video card (128 MB RAM), a NEC DVD-RW drive,
and a TEAC floppy drive) has a system temp of 90 f and CPU temp of 112
f. Again, that's with the stock AMD heatsink/fan and no overclocking.
 
A

Al Smith

Holy cow, talk about a brain fart. That was incorrect what I said
before. The _system temp_ stays well under 100 f. The CPU temp
averages between 40-50 c. That's with the stock AMD heatsink/fan, and
no overclocking.
Click to expand...

Still pretty good CPU temperature, on the upper end.
 
D

David Maynard

Al said:
What you say makes perfect sense, and I did think of it after changing
the direction of the fan's air flow. I'm surprised it made so much of a
difference, however. Five degrees C is considerable! In my setup, a
front mounted fan is not really a good option because the ribbon cables
and wires would hang down in front of it and spoil the air flow. I
mounted the rear fan high because that's where the mounting holes were.

I wish my box were running a bit cooler. The Thermaltake fan is fairly
quiet, which is what I needed (the stock AMD fan was driving me nuts
with its buzzing), but it isn't as good at cooling as the AMD -- simply
because it runs under 3000 rpm, whereas the AMD fan would kick up to
6000 rpm when required by CPU temperature. Mind you, the Thermaltake is
a superior heatsink and fan, but you can't compensate with copper fins
for double the fan blade speed.

My next move, if I feel like spending the cash, will be to upgrade my
power supple to a two-fan, extra quiet PSU (I was looking at an Ion in
the local shop) that should move more air more quietly than my present
PSU. I doubt the advantage in heat reduction and noise reduction will be
very much, so I'm in no hurry to do this.

Probably what I should do is get some Arctic Silver and try reseating my
CPU heatsink -- I suspect some of the CPU heat may be due to a poor
contact with the zinc oxide paste that I applied to the Thermaltake.
Then again, reseating it may make no difference at all.
Click to expand...

If you want quiet *and* good cooling in a CPU heatsink you need to use the
largest fan possible because a slower speed big fan will move more air than
a high speed smaller fan. That would be something like a thermalright, all
copper, SLK900 or SLK-947 (better) with a 92mm fan. For just about the best
possible cooling get an SP97.

Now, something I've been just itching to try because it looks mechanically
ideal, but haven't gotten around to because everything I have already
works, is the Thermaltake SilentTower with an 90mm (they claim) fan on one
side and the other side ducted straight to the rear fan exhaust port. That
way the single fan, which they claim is only 21db to start with, is sound
dampened inside the case and does double duty as CPU heatsink blower AND
case fan. The question is how much airflow drop there would be from the
duct, but one could always add the output side fan as an added boost.
 
D

David Maynard

ToolPackinMama said:
ToolPackinMama wrote:




::sigh::

AMD Athlon XP 2400+ CPU. Gee, I'm really batting a thousand today.
Click to expand...

Hehe. You sure it's an Athlon?
 
T

ToolPackinMama

David said:
If you want quiet *and* good cooling in a CPU heatsink you need to use the
largest fan possible because a slower speed big fan will move more air than
a high speed smaller fan.
Hmm!

Now, something I've been just itching to try because it looks mechanically
ideal, but haven't gotten around to because everything I have already
works, is the Thermaltake SilentTower
Click to expand...

FWIW:

http://www.thermaltake.com/coolers/cl-p0025/cl-p0025silentTower.htm
 
T

ToolPackinMama

Al said:
Still pretty good CPU temperature, on the upper end.
Click to expand...

Yeah, I'm satisfied. FWIW, I only have the one exhausting case fan
(side panel: came with case), plus PS fans, to cool the interior.
 
T

ToolPackinMama

<<*Note SilentTower is not compatible with any AMD K7 motherboard
without mounting holes on it>>

Can anybody please explain to me what is meant by that?
 
D

David Maynard

ToolPackinMama said:
ToolPackinMama wrote:




<<*Note SilentTower is not compatible with any AMD K7 motherboard
without mounting holes on it>>

Can anybody please explain to me what is meant by that?
Click to expand...

Yeah, the thing mounts via 4 holes in the motherboard around the socket;
not a 'spring clip'.

Technically those holes are supposed to be there but with it being so
common to use spring clips some, perhaps most, motherboard manufacturers
don't put them in because it gives a little more flexibility when routing
the circuit traces if the holes aren't in the way.
 
G

Gianmaria Fontana di Sacculmino

The front fan is useful for two reasons:
Click to expand...

It is obvious that, about this subject, there are at least two
different schools of thought :)
 
R

ric

Gianmaria said:
It is obvious that, about this subject, there are at least two
different schools of thought :)
Click to expand...

Yeah, but explaining fan performance isn't really a "school of thought."
Case static pressure prevents rear exhaust fans from reaching even close
to their published CFM. Adding a front fan decreases static pressure,
and increases rear fan CFM. Fact.
 

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