Reducing case temp

  • Thread starter Thread starter Lee MacMillan
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Lee MacMillan

How much does the video card contribute to case temperature? If I switch
from a Radeon 256MB 9600XT (which has a fan) to a fanless, 128MB Radeon
9250, will my case temp go down a few degrees?

FYI, system is Athlon XP 2700+, tower case, inlet and exhaust fans and case
temp runs about 35C with a 70F ambient. I can drop the case temp 4C-5C by
removing the front cover so I have some airflow issues.
 
Lee MacMillan said:
How much does the video card contribute to case temperature? If I switch
from a Radeon 256MB 9600XT (which has a fan) to a fanless, 128MB Radeon
9250, will my case temp go down a few degrees?

FYI, system is Athlon XP 2700+, tower case, inlet and exhaust fans and
case
temp runs about 35C with a 70F ambient. I can drop the case temp 4C-5C by
removing the front cover so I have some airflow issues.
Click to expand...

You are thinking in terms of temperature at a specific sensor. The question
shouldn't be how to lower the temperature, it should be how to correct the
airflow. But then, we don't even know if you have an airflow problem. With
the front cover removed, you DO have an airflow problem.

I need to back up a bit. Cases cool by circulating air through specific
areas. If you remove a cover, temperature might be cooler at a specific
sensor, but you will have less airflow -where needed-, leading to hot spots.
Cases can not cool properly with a cover removed, in other words. Leave the
covers ON unless you are actively troubleshooting. Even then, figure out
what the problem is, fix it, and get the covers back on ASAP.

WHAT, specifically, leads you to think you have a temperature problem to
begin with? 35C with 70 ambient sounds about right. A little high
possibly, but nothing to worry about, and probably due to where the sensor
is located. For example, right behind a hard drive or up top near the PSU
will give really high readings.

Oh, and switching to a passively cooled vid card will probably -increase-
case temp, depending on where the sensor is located. Again, it's about
airflow. Less airflow will result in more heat buildup. That wouldn't be a
problem, but if your goal is to reduce case temp. (WHY?!?), then that's the
wrong way to do it, by switching the video card.

After re-reading what you wrote, I'd suggest you remove (or just unplug) the
exhaust fan to lower the case temp. I know that's counter-intuitive, as it
would seem that more fans must be better. But it's best to balance inflow
air with exhaust air. Right now you've got an imbalance of more exhaust
than intake, assuming your power supply has an exhaust fan(s) that pulls air
from inside the case. In other words, the exhaust fan might be sucking hot
air out of the PSU and back into the case. Or at best, reducing airflow
through the PSU, again causing case temp to rise.

But then again, I don't think you need to lower case temp at all, so you
should post why you think you have a heat problem. -Dave
 
I agree with everything except this statement:
, I'd suggest you remove (or just unplug) the
exhaust fan to lower the case temp.

Removing the exhaust fan will definitely increase his Case Temp.
He needs to be sure that the airflow going in is slightly better than the
airflow going out.
This will result in Positive Pressure which will keep dust out as well as
keep the case cooler.
Pushing 60CFM of air in and removing 50cfm as an example
Other than that I see no real problem with his temp....My Inside case temp
is about 12 F above room temp...his is a little higher.putting a Video Card
with no fan inside will bring the temp up a little more and as such he would
need to look at increasing the movement of air inside his case...fans that
push more air are an easy choice.
Looking at the CPU cooler is another alternative...Quite a few aftermarket
coolers do a better job than the OEM ones.
peter
 
peter said:
I agree with everything except this statement:
, I'd suggest you remove (or just unplug) the
exhaust fan to lower the case temp.

Removing the exhaust fan will definitely increase his Case Temp.
He needs to be sure that the airflow going in is slightly better than the
airflow going out.
This will result in Positive Pressure which will keep dust out as well as
keep the case cooler.
Pushing 60CFM of air in and removing 50cfm as an example
Click to expand...


Exactly. That's why I suggested unplugging the exhaust fan. Right now, I
think he's got two or three out and one in (depending on how the PSU is
configured). So he's got negative pressure. To get to positive pressure,
the least he should do is unplug an exhaust fan. Maybe add another fan to
pull air into the case, as well.

But again, I don't think he's got a case temp. problem at all. -Dave
 
Lee said:
How much does the video card contribute to case temperature? If I
switch from a Radeon 256MB 9600XT (which has a fan) to a fanless,
128MB Radeon 9250, will my case temp go down a few degrees?

FYI, system is Athlon XP 2700+, tower case, inlet and exhaust fans
and case temp runs about 35C with a 70F ambient. I can drop the case
temp 4C-5C by removing the front cover so I have some airflow issues.
Click to expand...

35c for any Athlon XP is pretty good going, don't worry about it.

SteveH
 
Dave said:
You are thinking in terms of temperature at a specific sensor. The
question shouldn't be how to lower the temperature, it should be how to
correct the airflow. But then, we don't even know if you have an airflow
problem. With the front cover removed, you DO have an airflow problem.

I need to back up a bit. Cases cool by circulating air through specific
areas. If you remove a cover, temperature might be cooler at a specific
sensor, but you will have less airflow -where needed-, leading to hot
spots. Cases can not cool properly with a cover removed, in other words.
Leave the covers ON unless you are actively troubleshooting. Even then,
figure out what the problem is, fix it, and get the covers back on ASAP.

WHAT, specifically, leads you to think you have a temperature problem to
begin with? 35C with 70 ambient sounds about right. A little high
possibly, but nothing to worry about, and probably due to where the sensor
is located. For example, right behind a hard drive or up top near the PSU
will give really high readings.

Oh, and switching to a passively cooled vid card will probably -increase-
case temp, depending on where the sensor is located. Again, it's about
airflow. Less airflow will result in more heat buildup. That wouldn't be
a problem, but if your goal is to reduce case temp. (WHY?!?), then that's
the wrong way to do it, by switching the video card.

After re-reading what you wrote, I'd suggest you remove (or just unplug)
the exhaust fan to lower the case temp. I know that's counter-intuitive,
as it would seem that more fans must be better. But it's best to balance
inflow air with exhaust air. Right now you've got an imbalance of more
exhaust than intake, assuming your power supply has an exhaust fan(s) that
pulls air from inside the case. In other words, the exhaust fan might be
sucking hot air out of the PSU and back into the case. Or at best,
reducing airflow through the PSU, again causing case temp to rise.

But then again, I don't think you need to lower case temp at all, so you
should post why you think you have a heat problem. -Dave
Click to expand...

I should have been more to the point. It's actually CPU temp I want to
reduce. I have an Athlon 2700+ and it runs around 50C at idle at 70F
ambient. I used a good quality heatsink (all copper) and fan so I was
thinking if I reduced case temp several degrees, that would bring down CPU
temp also (they seem to track pretty close with the CPU always about 15C
above the case. From what's been posted here and some additional research,
I'm thinking maybe 50C isn't all that bad for CPU temp. I don't do too much
CPU intensive work so it doesn't get much hotter than that (although last
summer with 80F ambient, it got to 65C during the virus scan.

Thanks for your detailed explanation.

Lee
 
I should have been more to the point. It's actually CPU temp I want to
reduce. I have an Athlon 2700+ and it runs around 50C at idle at 70F
ambient. I used a good quality heatsink (all copper) and fan so I was
thinking if I reduced case temp several degrees, that would bring down CPU
temp also (they seem to track pretty close with the CPU always about 15C
above the case. From what's been posted here and some additional
research, I'm thinking maybe 50C isn't all that bad for CPU temp.
Click to expand...

No, you want to keep that around 65C or lower, preferably. It sounds like
your system is fine. -Dave
 
Dave said:
No, you want to keep that around 65C or lower, preferably. It sounds like
your system is fine. -Dave
Click to expand...

Thanks Dave. Since my previous chips (1800+ and 2200+) both ran CPU temps
in the mid to upper 30s, I was a little concerned about the 2700+.
Apparently that chip just runs quite a bit hotter.
 
I should have been more to the point. It's actually CPU temp I want to
reduce. I have an Athlon 2700+ and it runs around 50C at idle at 70F
ambient. I used a good quality heatsink (all copper) and fan so I was
thinking if I reduced case temp several degrees,
Click to expand...

What make/model HS/F are you using on your CPU?
that would bring down CPU
temp also (they seem to track pretty close with the CPU always about 15C
above the case. From what's been posted here and some additional research,
I'm thinking maybe 50C isn't all that bad for CPU temp.
Click to expand...

No, it's not.

I don't do too much
CPU intensive work so it doesn't get much hotter than that (although last
summer with 80F ambient, it got to 65C during the virus scan.
Click to expand...

Well, you could check and make sure all the crud has been
removed from between the HS fins and the fan. You'ld be
surprised what a good cleaning can do for you. Also reapply the
thermal grease between the HS and the cpu.
Thanks for your detailed explanation.

Lee
Click to expand...

Bill
 
I am a little confused now..case temp is at 35 and CPU temp is at
50.........that's the way I read that..is that right??
I would endeavor to bring the CPU temp down.....my 64x2 3500 runs at 42 .I
know 50 is safe but the cooler the better.
Could you list your case..type of fans..and what heatsink/fan you are using.
We might be able to suggest better cooling.
I run 2x 120mm fans..one in front...one out high back...Both Scythe's they
run nice and quiet but push a lot of air.
I also have a 120mm Scythe on my Thermalright Heatsink with a Generic Door
fan blowing cool air in towards the CPU.
these are the Scythe's I use
http://www.ncix.com/products/index.php?sku=17749&vpn=SFF21F&manufacture=Scythe.
My room temp is about 69/71 with an internal case temp of 78/80(case has a
probe which I have attached fairly high in the case and out of the way of
direct air circulation.
I am happy with my temps and even a mild Overclock and running memtest or
Orthos does not push the temp of the CPU too much past 50.
I always try for a nice steady low Temp at a quiet noise level.
peter
 
Actually, the CPU temp is typically 11-12C higher than the case temp so when
the CPU is 50C, the case would be around 38C.

I don't remember all the brands. The case is a tower, about 7 or 8 years
old. No side vents. I have two 3-speed fans (80mm), both set on high and
running about 2600 rpm, one bringing air in the front, the other exhausting
out the back plus the PSU fan (a Rosewill 430 watt). I believe the CPU
heatsink is a Thermalright. It's all copper. The CPU fan is a Delta,
pretty much a standard size (60mm). It runs about 4900 rpm according to
MBM. The case is in a computer desk with no obstruction on the back side.
I leave the door on the front open 4-8". If the door is closed, temps go up
2-3C.

The only reason I have been a little concerned is that my previous CPUs
(1800+ and 2200+) both ran in the high 30s. Apparently the 2700+ just runs
quite a bit warmer. Because the PC sits in the same room with the TV, I
have tried to keep the noise level down so I picked the case fans for their
low noise.

Lee
 
peter said:
I am a little confused now..case temp is at 35 and CPU temp is at
50.........that's the way I read that..is that right??
I would endeavor to bring the CPU temp down.....my 64x2 3500 runs at 42 .I
know 50 is safe but the cooler the better.
Could you list your case..type of fans..and what heatsink/fan you are
using.
We might be able to suggest better cooling.
I run 2x 120mm fans..one in front...one out high back...Both Scythe's they
run nice and quiet but push a lot of air.
I also have a 120mm Scythe on my Thermalright Heatsink with a Generic Door
fan blowing cool air in towards the CPU.
these are the Scythe's I use
http://www.ncix.com/products/index.php?sku=17749&vpn=SFF21F&manufacture=Scythe.
My room temp is about 69/71 with an internal case temp of 78/80(case has a
probe which I have attached fairly high in the case and out of the way of
direct air circulation.
I am happy with my temps and even a mild Overclock and running memtest or
Orthos does not push the temp of the CPU too much past 50.
I always try for a nice steady low Temp at a quiet noise level.
peter
Click to expand...

Experiment with reducing the exhaust fan speed. The problem with
a high flow exhaust fan is that it produces a wind tunnel effect in
the case with the airflow bypassing internal components. I have
an Antec P182 case which has 120 mm exhaust fans on the back
and top. Antec recommends running these fans at lowest speed.
I found that increasing the speed by just one notch caused my
CPU temp to jump by about 3 - 4*C.
 
I think your problem is a combination of same amount of air in as out and
the size of that heatsink fan...60mm??
Copper is a nice metal for a heatsink it really absorbs the heat BUT it
needs a good sized fan to dissipate that heat .
My other system has a nice Copper fin system on the Northbridge but without
a fan it just radiates the heat into the case..but with the addition of a
specific fan I dropped the temps about 8 degrees with the fan blowing across
those copper fins and pushing the hot air towards the rear exhaust
fan.Sometimes one needs to be a little creative in their cooling .
peter
 
How much does the video card contribute to case temperature? If I switch
from a Radeon 256MB 9600XT (which has a fan) to a fanless, 128MB Radeon
9250, will my case temp go down a few degrees?

FYI, system is Athlon XP 2700+, tower case, inlet and exhaust fans and case
temp runs about 35C with a 70F ambient. I can drop the case temp 4C-5C by
removing the front cover so I have some airflow issues.
Click to expand...

Became a non-issue for me when I got an all aluminum Antec Lanboy case
a couple years ago. Two 120mm fans - one intake front of the 5-bay HD
rack, one backplane exhaust below the PS. Issue then become from heat
to dust build up - Fuzzboy. I like it more than not though.
 
Became a non-issue for me when I got an all aluminum Antec Lanboy case
a couple years ago. Two 120mm fans - one intake front of the 5-bay HD
rack, one backplane exhaust below the PS. Issue then become from heat
to dust build up - Fuzzboy. I like it more than not though.
Click to expand...


That's how I moded my case--120mm fan in front and one 120mm fan at
the back. I slowed down the fans a little to decrease noise. Also
replaced the northbridge fan with a heatsink. Reducing cabling and/or
neatly managing cabling (with Velcro or cable ties) will improve
airflow to some extent.
 
That's how I moded my case--120mm fan in front and one 120mm fan at
the back. I slowed down the fans a little to decrease noise. Also
replaced the northbridge fan with a heatsink. Reducing cabling and/or
neatly managing cabling (with Velcro or cable ties) will improve
airflow to some extent.
Click to expand...

After this - seriously, a passively cooled, copper-tubed, modest CPU/
GPU, all quietly silent setup, would be nothing short of a
revelation. Ah well, better safe than sorry - and cool is a good
thing for going on at least a 3-yr-old 756 Athlon 3000, AGP 8500
Redeon, w/ 250G Seagates galore. Only thing that semi-flaked out was
three NEC DVDs, 3500-3540-3550 series
 
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