Attaching 80mm fan to original Athlon 2500 HSF

[Harry Muscle]

I'm looking for feedback on the idea of attaching a 80mm fan onto the
original HSF (Ajigo MF035-032) that came with my Athlon 2500 in order to get
the full load temp down from 72C to around 60C. The original 60mm fan is
rated at only 18.5CFM, which seems quite low. I could stick on a Vantec
Stealth 80mm fan that runs quiter and pumps 27CFM, which is about 50% extra
air flow. Is it possible that this would make enough difference to get me
down about 10C? Or should I look for a better heat sink also? In case it
matters, my case is 24C.

If you want more info about my reasoning on all of this read on ...

I currently have a Asus A7N8X Deluxe Rev. 2.0 with a Athlon XP 2500+ running
at 200Mhz * 9.5 with the stock HSF. Unfortunately I'm already hitting temps
of 72C on the diode (at full load), which I'm not comfortable with. Since I
don't like noise, and I don't want to overclock anymore than right now, I'm
not looking for a super powerfull HSF. I'm also one of those people you
worries about the warranty, etc. and would rather stick to the manufacturers
suggestions on what can be attached to the CPU. This means that I don't
want to go over the recommened 300g weight of the HSF and I would like to
stick with using a thermal pad instead of paste especially due to the danger
of thermal pump out.

Since the original heat sink is very close to 300g and is made of a copper
base with aluminum fins bonded to it, I'm thinking that I'm probably not
going to find a much better heatsink without going over the weight limit.
Am I correct in assuming that weight to a large extent governs how good a
heat sink can be (exluding poor designs, etc.).

So if I'm not going to find a much better heatsink for my needs, it only
makes sense that I simply change the fan, instead of getting a whole new
combination and wasting money.

Thank you for all the feecback,
Harry

 

[The TweakOholic]

72C? If that is really your CPU temp. your HS is not mounted properly!
You'd better get that problem solved before your CPU becomes a keychain
ornament.

 

[Harry Muscle]

72C? If that is really your CPU temp. your HS is not mounted properly!
You'd better get that problem solved before your CPU becomes a keychain
ornament.

It idles around 43C (this is the diode reading, not the socket which idles
around 34C, and only goes to the mid 50s under full load). I'm using the
original thermal pad, which might contribute a little to the heat, but I'm
pretty sure the HSF is on properly (for example its quite hot, so heat is
being transfered to it, but I'm thinking there's not enough airflow to get
the heat away from it ... ie: my original post)

Thanks,
Harry

 

[Harry Muscle]

Are you sure the HS is mounted the right way and not backwards?
72C is getting dangerous!!!

Have a quick look here at the heatsink install videos just to make sure!
http://tinyurl.com/3ue5

Ed

The heatsink is hot to the touch ... which makes me think it's on right. I
followed the instructions that came with the retail Athlon to the letter, so
I'm pretty sure it's on right. I'm just thinking it's not enough airflow
(18.5CFM ... which is quite low).

Btw, this is the diode reading, the socket is a good 10-15C cooler. The
diode reading idles around 43C.

Thanks,
Harry

 

[Ed]

Are you sure the HS is mounted the right way and not backwards?
72C is getting dangerous!!!

Have a quick look here at the heatsink install videos just to make sure!
http://tinyurl.com/3ue5

Ed

 

[rstlne]

It idles around 43C (this is the diode reading, not the socket which idles
around 34C, and only goes to the mid 50s under full load). I'm using the
original thermal pad, which might contribute a little to the heat, but I'm
pretty sure the HSF is on properly (for example its quite hot, so heat is
being transfered to it, but I'm thinking there's not enough airflow to get
the heat away from it ... ie: my original post)

Thanks,
Harry

so where did the 72c come from?

 

[Ed]

The heatsink is hot to the touch ... which makes me think it's on right. I
followed the instructions that came with the retail Athlon to the letter, so
I'm pretty sure it's on right. I'm just thinking it's not enough airflow
(18.5CFM ... which is quite low).

Btw, this is the diode reading, the socket is a good 10-15C cooler. The
diode reading idles around 43C.

Thanks,
Harry

Things I would check,
CPU fan is blowing onto the heat sink, not sucking.

PSU is blowing the heat out of the case and not into the case.

Install at least one rear case fan blowing out of case, add a front case
fan helps but not nearly as much.

I'm using 80mm case fans on 2 systems for CPU fans, but they have better
heatsinks then the AMD PIB parts, at full loads the 80mm don't cool as
good as the original fans do, at idle there is basically no difference.


Ed

 

[Harry Muscle]

so where did the 72c come from?

It's the reading of the internal diode when I'm running the CPU at full load
(ie: prime95).

Harry

 

[Ed]

It idles around 43C (this is the diode reading, not the socket which idles
around 34C, and only goes to the mid 50s under full load). I'm using the
original thermal pad, which might contribute a little to the heat, but I'm
pretty sure the HSF is on properly (for example its quite hot, so heat is
being transfered to it, but I'm thinking there's not enough airflow to get
the heat away from it ... ie: my original post)

Are you using MBM?
When I built my system some guy posted this...
Do not use both W83L785T-S and W83L785T-S Diode (Asus 4) simultaneously
in MBM or results will be incorrect.

Ed

 

[Harry Muscle]

Are you using MBM?
When I built my system some guy posted this...
Do not use both W83L785T-S and W83L785T-S Diode (Asus 4) simultaneously
in MBM or results will be incorrect.

Ed

Just checked, nope, it doesn't even allow me to pick both. If one is
already selected, when I trying to select the other one for one of the other
monitors ... it simply puts it back to none.

Thanks though,
Harry

 

[Harry Muscle]

Things I would check,
CPU fan is blowing onto the heat sink, not sucking.
Check.


PSU is blowing the heat out of the case and not into the case.
Check.


Install at least one rear case fan blowing out of case, add a front case
fan helps but not nearly as much.

I've got two of them right behind the CPU sucking air out. Another in the
front blowing air in. Case stays at a steady 24C. Room temp is 22C.

I'm using 80mm case fans on 2 systems for CPU fans, but they have better
heatsinks then the AMD PIB parts, at full loads the 80mm don't cool as
good as the original fans do, at idle there is basically no difference.

However, what if the 80mm fan delivers an extra 50% more airflow over the
original 60mm? Or are you saying that the increased airflow wouldn't change
anything?

Ed

P.S. Does anyone have a similar setup as me (Athlon 2500 with original HSF
and thermal pad)? Could you share your temps with me (especially the
internal diode temp as read by MBM5) after running prime95 for a couple of
minutes on the max heat torture test setting. Thanks.

 

[AJ]

I'm looking for feedback on the idea of attaching a 80mm fan onto the
original HSF (Ajigo MF035-032) that came with my Athlon 2500 in order to get
the full load temp down from 72C to around 60C. The original 60mm fan is
rated at only 18.5CFM, which seems quite low. I could stick on a Vantec
Stealth 80mm fan that runs quiter and pumps 27CFM, which is about 50% extra
air flow. Is it possible that this would make enough difference to get me
down about 10C? Or should I look for a better heat sink also? In case it
matters, my case is 24C.

I put a Vantec about two inches from the retail HSF and it dropped the
temps 15C. That's a 2500+ @ 3200+. So your idea is a good one. The
weight specs are only for PC's in transit like LAN boxes for gaming.
The Volcano 11+ keeps one of my Bartons 2500+ @ 3200+ below 44C at all
times.
http://www.thermaltake.com/products/heatsink/v11plus.htm

 

[Ed]

However, what if the 80mm fan delivers an extra 50% more airflow over the

original 60mm? Or are you saying that the increased airflow wouldn't change
anything?

Sure, more force, more air the better.

My 80mm fans hang over the left/bottom side of the HS so they also blow
air on the chipset and V regulators, works pretty good, but most case
fans don't have very good pressure, results will vary.

 

[The TweakOholic]

Replace the stock HSF with a Thermalright SLK-800 or 900 with a nice and
quite Vantec Stealth fan and use thermal paste. If you can't buy the
Stealth fan where you live, get a fan speed control unit to control the
speed of whatever fan you decide to use. Vantec makes nice fan speed
control units as well....

www.thermalright.com
www.vantecusa.com

 

[Ernst]

I'm looking for feedback on the idea of attaching a 80mm fan onto the
original HSF (Ajigo MF035-032) that came with my Athlon 2500 in order to get
the full load temp down from 72C to around 60C. The original 60mm fan is
rated at only 18.5CFM, which seems quite low. I could stick on a Vantec
Stealth 80mm fan that runs quiter and pumps 27CFM, which is about 50% extra
air flow. Is it possible that this would make enough difference to get me
down about 10C? Or should I look for a better heat sink also? In case it
matters, my case is 24C.

If you want more info about my reasoning on all of this read on ...

I currently have a Asus A7N8X Deluxe Rev. 2.0 with a Athlon XP 2500+ running
at 200Mhz * 9.5 with the stock HSF. Unfortunately I'm already hitting temps
of 72C on the diode (at full load), which I'm not comfortable with. Since I
don't like noise, and I don't want to overclock anymore than right now, I'm
not looking for a super powerfull HSF. I'm also one of those people you
worries about the warranty, etc. and would rather stick to the manufacturers
suggestions on what can be attached to the CPU. This means that I don't
want to go over the recommened 300g weight of the HSF and I would like to
stick with using a thermal pad instead of paste especially due to the danger
of thermal pump out.

Since the original heat sink is very close to 300g and is made of a copper
base with aluminum fins bonded to it, I'm thinking that I'm probably not
going to find a much better heatsink without going over the weight limit.
Am I correct in assuming that weight to a large extent governs how good a
heat sink can be (exluding poor designs, etc.).

So if I'm not going to find a much better heatsink for my needs, it only
makes sense that I simply change the fan, instead of getting a whole new
combination and wasting money.

Thank you for all the feecback,
Harry

If you decide to mount the 80mm fan, build a funnel like mount that
raises the fan about 3/4 of an inch above the heatsink. There was a
website where they did some tests and they figured the fan motor was
blocking air flow in the middle of the fan and heat sink where it's
needed most. Cooling improved just by raising the stock fan .
If I can find this site again I'll post the URL.
It stands to reason that if you can channel more cfm through the
heatsink you'll keep it cooler.
Ernst

 

[Wes Newell]

So if I'm not going to find a much better heatsink for my needs, it only
makes sense that I simply change the fan, instead of getting a whole new
combination and wasting money.

I'd do two things. Change the fan and scrape the thermal pad off and use
thermal paste. And if I had to wait long for the fan, I'd go ahead and
replace the thermal pad now. That alone should help. Fan wise, I'd get
more than 27cfm and use a fan control to keep the speed down. I'd go for
at least 36cfm minimum.

 

[Aussie]

Get a Volcano 11+ and ThermalTake duct...Seperate the fan from the heatsink
, attach the duct onto the heatsink and fan on to duct..Let it rock'n
roll.Keeps my 2500+ @ 2.329 pretty cool , 39-40*C under load...Which is
playing Halo for 2 hrs.

 

[Fishface]

scrape the thermal pad off and use thermal paste.

When I was stress testing with inadequate case cooling--
what better time?-- my Barton was reaching 70º C. I
then removed the thermal pad and lost about 5º C under
load conditions. I still replaced the HSF with the Silent
Boost, and the temps are only a few degrees cooler.
There's a lot of heat being generated, and only a small
surface area of the thermal interface. I'm wondering why
they aren't using silver-- it's not that expensive. Maybe
oxidation or something...

 

[Harry Muscle]

I'd do two things. Change the fan and scrape the thermal pad off and use
thermal paste. And if I had to wait long for the fan, I'd go ahead and
rep the thermal pad now. That alone should help. Fan wise, I'd get
more than 27cfm and use a fan control to keep the speed down. I'd go for
at least 36cfm minimum.

Thanks to everyone who replied, here's what I've done so far. I got one of
those 80mm to 60mm adapters, stuck on a Vantec Stealth fan, and the temps
dropped to an amazing (sarcasm) 69C after two mins of prime95. Changed to
another fan that's like five times louder, dropped just one more degree. So
I thought that it's either a crappy heatsink or heat isn't being transfered
to it too well. So I took it off, scraped and cleaned of the termal pad,
put on a very very thin layer of Ceramique (by Arctic Silver). Put
everything back together with the 80mm Vantec Stealth Fan, and after two
mins of prime95 I was only reaching 57C, that's a 12C drop, wow. I let it
run for about half an hour, and it never reached over 63C, which I'm quite
happy with.

However, when I took the heatsink off, I got a good look at it again, and I
noticed that there are quite a few machine lines in the bottom of the sink,
there almost like little groves all llel to each other. So I'm thinking
I might do a little lapping on the sink. Anyone know any good guides on the
web on how to lap a heatsink? I know the basic principle behind lapping,
but I'm just looking for specifics (ie: which grade of sandpaper, etc.).

Also, when people say to put on a very very thin layer of thermal compound,
how thin are we talking. I usually spread this stuff with the edge of an
exacto knife. Should I be able to see the core through this stuff or should
it be just enough to make the core invisible?

Thanks,
Harry

 

[Jim Banks]

<snip>
However, when I took the heatsink off, I got a good look at it again,
and I noticed that there are quite a few machine lines in the bottom
of the sink, there almost like little groves all llel to each
other. So I'm thinking I might do a little lapping on the sink.
Anyone know any good guides on the web on how to lap a heatsink? I
know the basic principle behind lapping, but I'm just looking for
specifics (ie: which grade of sandpaper, etc.).
<snip>

Heat Sink Lapping Guide http://tinyurl.com/q6cn