"Andre said:
is 47 cel and 61 cel after 3dmarks 3 to high.i have a p4c 800e deluxe,2 gig
ram ,2 dvd burners,3 harddrives,ati x800xt with silencer 4 cooler,aerocool
ht 101 heat sink with 2 fans,1 120 front fan ,2 80 rear fans,1 80 side fan.I
am sure they are all flowing the correct way. I just installed the ht 101
with artic silver 5.I am pretty sure that was the same temp with stock
heatsink.plus running a p4 3.2 Prescott. thanks .
Remove the side panel of the PC.
Do the temperatures drop ?
If they do, it means that there may not be enough openings in
the case for the fans to do their job.
I have an Antec Sonata case, with a 120mm fan on the back.
Even though the 120mm is spinning at a reasonable rate of
speed, I wasn't really getting good cooling. With the side
off the case, I noticed the speed of the fan dropped. That
told me there were not enough vent holes in the case, to
supply a 120mm fan. By removing some of the grillwork
from the front of the case, I got an 8 degree C drop in
temperatures.
The basic theme for fans is:
1) Pull air into the case via a fan down low, in the front of
the case.
2) Exhaust air from the top rear of the case (using both the
PSU fan and a separate fan).
3) Try to balance the sum of the CFM (cubic feet per minute)
ratings on fans pulling air into the case, with the CFM
rating of the fans exhausting the case.
Following 1,2,3 above should keep dust accumulation to a minimum.
This site has a formula for calculating cooling:
http://www.chassis-plans.com/cooling_and_noise.html
CFM = 3.16 x Watts / Delta_T_degrees_F
What this formula relates, is how much warmer the case air
will be, than the air in the room (ambient temperature).
Say that we set the maximum allowable case air delta to
12.6F. That means if the room temperature is 72F, the
air inside the case will be 84.6F . AMD considers that to
be a reasonable limit to how much higher the case air
temperature should be allowed to get. (12.6F is about 7C.)
Using round numbers, I'll assume your computer uses 180W
internally while gaming.
CFM = 3.16 x 180 / 12.6 = 45CFM
A rough guess, is your 120mm fan is rated for 70CFM, which
should be sufficient if there is enough openings for the
air to get into the case. If the fan is starved for air,
the CFMs will drop.
Your CPU heatsink can only do its work, if the air inside
the case is cool. If the CPU heatsink/fan had a rating of
0.20 degrees C per watt, and the CPU dissipated 100 watts,
there would be a 20 degree C rise in temperature, between
the case air and the CPU temperature sensor. If you can
bring the case air temperature down, that helps bring down
the CPU temperature.
In other words, to improve your CPU temperature, you can
use a better heatsink/fan on the CPU (which reduces the
delta between CPU temperature and case air temperature)
and you could do a better job on case air cooling, which
would reduce the delta between the case air temperature
and the room air temperature.
Depending on which of those temperature differences is
larger, will determine whether you need to work on one
or both of those cooling issues.
So, go back and look at:
1) Room air temperature (check furnace thermostat)
2) Case air temperature (so-called motherboard temp in BIOS)
3) CPU temperature (also in the BIOS)
If (case_air - room_air) is less than 12.6 degrees F,
then your case cooling is pretty good.
If room temperature is 22C, case air delta is 7C, thermal
resistance of heatsink is 0.20 C/W, and processor power is
100 watts, the CPU temp will be 22+7+(0.20x100)=49C
at 100% gaming load. If you had a crappy heatsink on the
CPU (say 0.33C/W - higher is worse) then the temp would
be 22+7+(0.33x100)=62C. In that case, a better CPU
heatsink/fan would help.
If the case air delta is 15C, and you have a good CPU
heatsink (0.20C/W), then 22+15+(0.20x100)=57C. In that
case, improving air circulation, either with more fans
or with more openings to allow the existing fans to work,
might allow you to get the case air delta down to 7C.
In this example, it really isn't possible to make a much
better air cooling CPU heatsink (i.e. lower than 0.20C/W).
You could consider a water block, and a
reservoir/radiator/fan located well away from the case,
as a way to get rid of the heat.
HTH,
Paul
