Thermal pad or Thermal paste?

[Vin]

hey there,

after some excessive amount of case modding to fit 4 additional
suckholes/blowholes (3 in the side case blowing IN and 1 on top of case
blowing OUT), i've finally managed to bring my case temperatures under
control -- about 6C above the room ambient (ambient is 28C, case is 34C).
But my case to cpu temperature delta has gone out of whack! previously with
my case open and a floor fan blowing into the case, the cpu temperatures
hovered about 18C above the case/system (when idle), but now it's a shocking
24-25C above the case temperature (currently 58-59C when idle). Thus I've
decided to chuck the retail AMD HSF and get myself a Thermalright SLK700
cooler.

Now that the backgrounder is done with, my actual question: should i use
thermal paste instead of a thermal pad with my new cooler? I've read that
AMD will void your CPU warranty if you use thermal paste/grease. Also would
thermal paste require any maintenance, like removing, cleaning and reseating
the cooler every few weeks?

thanks,
vin

 

[Rick]

hey there,

after some excessive amount of case modding to fit 4 additional
suckholes/blowholes (3 in the side case blowing IN and 1 on top of case
blowing OUT), i've finally managed to bring my case temperatures under
control -- about 6C above the room ambient (ambient is 28C, case is 34C).
But my case to cpu temperature delta has gone out of whack! previously with
my case open and a floor fan blowing into the case, the cpu temperatures
hovered about 18C above the case/system (when idle), but now it's a shocking
24-25C above the case temperature (currently 58-59C when idle). Thus I've
decided to chuck the retail AMD HSF and get myself a Thermalright SLK700
cooler.

Now that the backgrounder is done with, my actual question: should i use
thermal paste instead of a thermal pad with my new cooler? I've read that
AMD will void your CPU warranty if you use thermal paste/grease. Also would
thermal paste require any maintenance, like removing, cleaning and reseating
the cooler every few weeks?

thanks,
vin

IME the chances of actually using a cpu warranty are next to nil, so I
wouldn't let that stop me from using thermal grease. You'll almost
certainly get better cooling than with a pad.

Most thermal greases don't require maintenance unless you dismount
and remount the cpu (obviously).

My $.02

Rick

 

[Alan]

I agree with Rick, and I only use thermal grease. It lowers the temps
substantially.
A couple of weeks ago, I had to have a CPU replaced by AMD, they did so
without any problems. AMD is an excellent company to deal with.

Artic Silver has instructions on their site as to proper installation of
thermal grease. Minimal amount spread to the thinnest film is the secret to
best temps. I don't use Artic Silver though, rather I use some that came
with a Dr. Thermal heatsink.

Having said that, your CPU should not have risen more above the ambient temp
of the case. Did you remove the Themal material, clean the residue with
isopropol alcohol and replace it with a fresh one? I would also check your
mounting of the heatsink and the clip tension.

A rule of thumb is that with the heatsink rests at a similar temp above the
case, and 24C is too high. Look for 10C when idle and 15C under 100% use,
this will depend upon the effectiveness of your heatsink, and mounting.


Alan

 

[Vin]

i've read the thermal paste installation instructions on the AS3 web site.
the thermal paste installation is quite detailed and helpful, but i'm quite
confused about the cleaning of the cpu core/ceramic bit (cleaning the old
heatsink doesnt apply to me, as i'm replacing my stock HSF with the
thermalright 700)

how do i safely and properly clean the thermal pad residue from the cpu
core/ceramic? i checked with my local chemist, but he doesnt have any
isopropyl alcohol with him. also it's mentioned that if i use any other
cleaning agent, i'd still need to do a final cleaning with isopropyl
alcohol -- are there any other commonly available cleaning agents that i can
use?

another thing, do you directly dab a tissue paper with a cleaning agent and
then rub away the residue from the core/ceramic of the cpu? or would a
cotton bud be preferable?

thanks,
vin

 

[Joe727]

hey there,

after some excessive amount of case modding to fit 4 additional
suckholes/blowholes (3 in the side case blowing IN and 1 on top of case
blowing OUT), i've finally managed to bring my case temperatures under
control -- about 6C above the room ambient (ambient is 28C, case is 34C).
But my case to cpu temperature delta has gone out of whack! previously with
my case open and a floor fan blowing into the case, the cpu temperatures
hovered about 18C above the case/system (when idle), but now it's a shocking
24-25C above the case temperature (currently 58-59C when idle). Thus I've
decided to chuck the retail AMD HSF and get myself a Thermalright SLK700
cooler.

Now that the backgrounder is done with, my actual question: should i use
thermal paste instead of a thermal pad with my new cooler? I've read that
AMD will void your CPU warranty if you use thermal paste/grease. Also would
thermal paste require any maintenance, like removing, cleaning and reseating
the cooler every few weeks?

thanks,
vin

You might want to take a look at these Processor and Heatsink Installation
Videos available on the AMD site:

http://www.amd.com/us-en/Processors/TechnicalResources/0,,30_182_869_4348^6678,00.html

Joe

 

[Alan]

First you need to scrape off the thermal material, DO NOT USE A METAL
OBJECT, as this will scratch the surface. Plastic is better, and take your
time to be very careful. You must not scratch the chip surface or the
heatsink surface.

I have Isopropyl to clean remaining residue and remove any oils, so that is
what I now use. I cut small pieces of paper towel and use them, (oil free
and doesn't leave particles)

Before that I used a very slight amount of cleaning fluid (varsol type)
which is absolutely not recommended. However I was extremely careful and
made sure there was little to no residue left. Of course this is an oil
base, so it is not perfect, but it did work.

I have read in a newsgroup of people using things like goop-off and orange
citrus stuff, I believe these are not recommended either.
Others have used nail polish remover or acetone (they are same base), I
absolutely say NO to that, acetone will melt certain resins and damage the
surface.

Hope this helps,

Alan

 

[Peter van der Goes]

hey there,

after some excessive amount of case modding to fit 4 additional
suckholes/blowholes (3 in the side case blowing IN and 1 on top of case
blowing OUT), i've finally managed to bring my case temperatures under
control -- about 6C above the room ambient (ambient is 28C, case is 34C).
But my case to cpu temperature delta has gone out of whack! previously with
my case open and a floor fan blowing into the case, the cpu temperatures
hovered about 18C above the case/system (when idle), but now it's a shocking
24-25C above the case temperature (currently 58-59C when idle). Thus I've
decided to chuck the retail AMD HSF and get myself a Thermalright SLK700
cooler.

Now that the backgrounder is done with, my actual question: should i use
thermal paste instead of a thermal pad with my new cooler? I've read that
AMD will void your CPU warranty if you use thermal paste/grease. Also would
thermal paste require any maintenance, like removing, cleaning and reseating
the cooler every few weeks?

thanks,
vin

A dissenting opinion.
You've made significant changes to your case airflow, and achieved a
reduction in *case* temps with increased CPU temp. My first thought is that
you've mounted a fan(s) where cool air is blowing directly onto the
motherboard "case" temperature diode, while disrupting proper flow of cool
air to the HSF area. If you've managed to create a dead air area around your
CPU (quite possible if you've added a lot of inflow without adequate exhaust
near the CPU/HSF), it's your mods that have caused the CPU temp increase.
I'm offering this because you imply that you did nothing with your current
HSF while doing the case mods, correct? If that's true, there's no reason to
believe anything *but* the case mods affected the CPU temperature. If I'm
right (happens occasionally), you're going to be disappointed with the new
HSF, as no HSF can work efficiently if it's being fed hot air.

 

[Vin]

hi peter,

i can't really pinpoint any reason for the increased cpu temps since the
case mods were done after a lot of research -- my case currently has 1 rear
exhaust fan, 1 psu exhaust, 1 front/bottom intake, 3 side panel
intake/suckholes (1 bang opposite the cpu cooler with a duct, 1 blowing air
onto the agp slot, and 1 towards the hdd area on the bottom/front) and 1 top
blowhole exhausting hot air. The positions were chosen carefully and i've
also tried to balance the intake and outtake fans.

Thus i can't really understand why the temp delta (cpu to case) is much
higher than before (24C vs 18C previously). but do bear in mind, that the
actual CPU temperature is about the same now with the case closed as it was
with the case open and a huge floor fan blowing into it -- it's just the
cpu-case delta that has gone out of whack, which could suggest the heatsink
ain't doing it's job well, even though the case is cooler now.

vin

 

[Rick]

I think you missed Pete's point: cooler temps/increased airflow in
a case does not necessarily mean cooler temps/increased airflow
around a cpu. The additional fans might have created a dead spot
where airflow is needed most.

Blowholes on top of a case aren't as effective as blowholes near
or behind the cpu/agp area. Does your case have a fan cutout
under the psu exhaust? If not, get one that does.

Rick

 

[Phrederik]

after some excessive amount of case modding to fit 4 additional

suckholes/blowholes (3 in the side case blowing IN and 1 on top of case
blowing OUT), i've finally managed to bring my case temperatures under

Now that the backgrounder is done with, my actual question: should i use
thermal paste instead of a thermal pad with my new cooler? I've read that
AMD will void your CPU warranty if you use thermal paste/grease. Also would
thermal paste require any maintenance, like removing, cleaning and reseating
the cooler every few weeks?

The answer is PASTE! Leave it there unless you remove your heatsink.

My question is this...

WHY would you be punching holes all over your case if you didn't know the
simplest thing about cooling your CPU?

 

[kony]

hi peter,

i can't really pinpoint any reason for the increased cpu temps since the
case mods were done after a lot of research -- my case currently has 1 rear
exhaust fan, 1 psu exhaust, 1 front/bottom intake, 3 side panel
intake/suckholes (1 bang opposite the cpu cooler with a duct, 1 blowing air
onto the agp slot, and 1 towards the hdd area on the bottom/front) and 1 top
blowhole exhausting hot air. The positions were chosen carefully and i've
also tried to balance the intake and outtake fans.

Thus i can't really understand why the temp delta (cpu to case) is much
higher than before (24C vs 18C previously). but do bear in mind, that the
actual CPU temperature is about the same now with the case closed as it was
with the case open and a huge floor fan blowing into it -- it's just the
cpu-case delta that has gone out of whack, which could suggest the heatsink
ain't doing it's job well, even though the case is cooler now.

vin

With your configuration there aren't any significant airflow problems
around the CPU as others have speculated, the system is responding
_NORMALLY_ to the changes. You see the correct "delta (cpu to case)
because you aren't significantly reducing case temp at this point, you
are blowing a stream of air onto the chip taking the temp reading
(probably the southbridge). You would now need a external temp sensor
to take accurate reading, though it's not really necessary, the case
now has plenty of ventilation. The stock heatsink should be more than
enough to keep the system stable from a heat perspective unless the
room ambient temp is excessively high, which from your earlier temp
report it isn't. The primary reason to replace the heatsink at this
point would be to reduce noise, though the other fans might be louder
anyway.


Dave

 

[Vin]

hi dave,

so what you're telling me in a nutshell is that my case temperatures haven't
really dropped, they're about the same or maybe even 1-2C higher than when i
had a floor fan blowing into the case -- it's just so happens that the mobo
sensor reporting the case temp now has better airflow around it and is
'misreporting' the _GENERAL_ case temperature?

thanks,
vin

ps: i'm not expecting any miraculous reduction in the cpu temps with the
slk700, but when i installed my athlon xp a few months back, i used the
default thermal pad and from what i've been reading, all things being equal
thermal paste can definitely drop temperatures by 3-5C. Also the slk700
reportedly has a much better thermal resistance than the stock HSF, so i'll
let you know whether it made any difference or not come sunday

 

[kony]

hi dave,

so what you're telling me in a nutshell is that my case temperatures haven't
really dropped, they're about the same or maybe even 1-2C higher than when i
had a floor fan blowing into the case -- it's just so happens that the mobo
sensor reporting the case temp now has better airflow around it and is
'misreporting' the _GENERAL_ case temperature?

It's not misreporting the ambient case temp necessarily, but being a
sensor that takes the temp of that chip, it was never an accurate temp
sensor to begin with. I'm not really sure who started the trend of
calling it the "system" temp, and futher extending that to refer to
case ambient temp, but this notion is now so widespread...

Given that the chip creates heat internally, yet is being cooled by
lower-temp outside air, and that you have plenty of airflow in the
case, it's most likely that sensor is now registering nearer to
ambient case temp than ever before, but likely the reading is still
slightly higher, partially because the chip isn't 'sunk to anything
but mostly because even if it were, the heat source is in the
immediate vicinity of the sensor.

ps: i'm not expecting any miraculous reduction in the cpu temps with the
slk700, but when i installed my athlon xp a few months back, i used the
default thermal pad and from what i've been reading, all things being equal
thermal paste can definitely drop temperatures by 3-5C. Also the slk700
reportedly has a much better thermal resistance than the stock HSF, so i'll
let you know whether it made any difference or not come sunday

The SLK700 is definitely a better heatsink, though I'm not going to
hazzard a guess as to what the temp drop might be, but it should be
noticeable and/or quieter depending on the fan. I'm not fond of those
TMD fans but it's partially because an earlier revison was prone to
short-out, frying fan headers. Unfortunately I don't recall how to
tell which are the earlier revisions with this problem.


Dave

 

[David Maynard]

hi peter,

i can't really pinpoint any reason for the increased cpu temps since the
case mods were done after a lot of research -- my case currently has 1 rear
exhaust fan, 1 psu exhaust, 1 front/bottom intake, 3 side panel
intake/suckholes (1 bang opposite the cpu cooler with a duct, 1 blowing air
onto the agp slot, and 1 towards the hdd area on the bottom/front) and 1 top
blowhole exhausting hot air. The positions were chosen carefully and i've
also tried to balance the intake and outtake fans.

Thus i can't really understand why the temp delta (cpu to case) is much
higher than before (24C vs 18C previously). but do bear in mind, that the
actual CPU temperature is about the same now with the case closed as it was
with the case open and a huge floor fan blowing into it -- it's just the
cpu-case delta that has gone out of whack, which could suggest the heatsink
ain't doing it's job well, even though the case is cooler now.

vin

I agree with Peter in that your temperature readings, and the conclusions drawn,
are inconsistent with physics. In particular, one, or both, of the "case"
readings must not be actual case temperature (at least around the CPU socket).

Regardless of how good, or bad, the heatsink is, it didn't change and if case
temperature truly went down then the CPU temperature would go down the same
amount. I.E. The CPU heat IS going to 'flow' with the only question being what
temperature the CPU has to rise to in order to force it and, since the thermal
interface/ heatsink did not change, the temperature differential across it due
to that flow will be the same. So, as case temp varies, the CPU temperature will
follow in direct lockstep (assuming the same CPU loading/heat output). The fact
that it didn't change indicates SOME temperature reading is not what you think
it is.

What would help is to get an independent temperature probe and measure the
actual case temperature in a number of spots to see what is really going on in
there, and without that the rest is mainly guessing, but it's not unheard of for
the supposed 'case temp' to be influenced (heated) by the motherboard it's
mounted on (plus their location is not conducive to good airflow) and Peter's
suggestion that your additional fans, or one of them, are simply cooling IT, the
temperature sensor, more (so it reads lower) is a reasonable guess. The part
that I'm not so sure also follows is the airflow around the CPU socket being
disrupted (Don't get me wrong, his comment about case airflow disruption is
correct. It's just that he didn't have your follow up message giving CPU temps
to go on). Since you say the CPU temps are about the same as with the case sides
off, and a large fan blowing on it, I'd say the CPU socket airflow is just fine,
that the apparent 'case temp' difference is simply the motherboard sensor
being cooled more, and that your multi-fan hurricane setup is moving air as
well, or more, as the case open observation (with the difference being air
directly impinging on the case temp sensor, or the motherboard around it,
causing it to read lower).

Having said that, if you want lower CPU temps then your conclusion to get a
better heatsink is probably correct since it seems apparent that 'case flow' is
not the problem. It's just that you may also find that your 'high' case temp was
the motherboard sensor reading high and that adding some, or all, of those case
fans was not really needed.

 

[David Maynard]

hi dave,

so what you're telling me in a nutshell is that my case temperatures haven't
really dropped, they're about the same or maybe even 1-2C higher than when i
had a floor fan blowing into the case -- it's just so happens that the mobo
sensor reporting the case temp now has better airflow around it and is
'misreporting' the _GENERAL_ case temperature?

You can't draw those conclusions from the data. What we know is that the reading
from a temperature sensor you don't know anything about (such as were it's
located) is lower but that the CPU temp differential to it is higher.

Case temp may have gone down some but the amount (around the CPU) would be
reflected in the CPU temperature reading. I don't recall, however, seeing you
post same conditions, case closed, before and after numbers so we don't know how
much, if any, things changed under similar conditions (what I recall is a
comparison to case OPEN with a large fan blowing on it). I don't know from what
data you come up with the possible 1 to 2 C rise.

Without 'same conditions' data you cannot draw definite conclusions.

What we have are two temperature sensor readings, from a sensor you THINK (why?)
is 'case temp', at what would seem, and I stress SEEM, to be (nearly) the same
real (leaving aside, for the moment, possible dead spots and inside temperature
differentials) case temperature. Why would you presume the first one was 'right'
with the current one 'misreporting'? With no knowledge of what the REAL case
temperature is, and especially with an apparent measurement inconsistency, why
would you presume EITHER of them is 'right'?

Bringing back the 'aside', case temp where? Around the CPU socket? Around the
hard drive? Around the motherboard near the southbridge? Around the video card?
Maybe they're similar and maybe they're not.

If you 'really want to know' what the temperatures are then you need to get
something you know accurately measures temperature and measure the temperatures
in the places you want to know about. If all you want is to reduce CPU temps
then the data suggests you need a better heatsink as it appears 'more case flow'
is not affecting it.

Once you have a better heatsink you could try playing around with the case fans
to see which ones 'make a difference' to your temp readings and perhaps reduce
the noise.

 

[Vin]

hi david,

maybe all those case fans are a bit excessive, but after 3-months of having
a 350mm floorfan beside my left ear, my 'multi-fan hurrircane' setup is much
much quieter than the humming noise i can still experience in my head

and the real motivation behind all these mods was my 1-yr daughter has
started flinging stuff across the room now, and a few days back she holed
the tv remote into my then open computer case!

best,
vin

 

[AnthonyR]

What do you mean the chemist didn't have alcohol?
Do you not have rubbing alcohol in your house? here in the states every
house has a bottle, its used to clean wounds and stuff.
What do you use for scraped knee's?
AnthonyR.

 

[David Maynard]

hi david,

maybe all those case fans are a bit excessive, but after 3-months of having
a 350mm floorfan beside my left ear, my 'multi-fan hurrircane' setup is much
much quieter than the humming noise i can still experience in my head

Hehe. Good point.

and the real motivation behind all these mods was my 1-yr daughter has
started flinging stuff across the room now, and a few days back she holed
the tv remote into my then open computer case!

LOL

My brother in law had a similar problem with his 1 year old. Kid couldn't do
squat except instinctively knew how to cycle the front power switch. That's why
he wanted an Antec case with locking front door.

 

[Si]

I have an AMD 2000+ and was getting quite high temperatures reporting from
the bios (around 60c), so I took the large copper flower off and cleaned it
up with alcohol and stuck a thermal pad on. (this was advice from an
artical I read about how difficult it is to get a consistant layer across
the processor with paste). After warming up the pc I had crank my fan flat
out to keep it down to 70-75c!!!! That just didn't work at all.
I bought some silicon paste, cleaned it all up again......now it's running
52c with a slow fan speed, ready to overclock again. My system temp is 32c
with a large heatsink and for reference, it's about 21c here in UK.

What I've learnt is that it is important to get the grease as perfect as you
can manage. I used a razor blade to smooth the grease over the heatsink,
made sure I didn't put my fingers on any surface after I cleaned it and made
sure the pressure from the clamp on the heatsink was directly over the CPU
centre. That lot is so important, it made 20c diference!! so take your time
with it. I'm sure there are other greases that would do a better job, but
it's good enough for me.

Now to see if I can get 1.6G to 1.7 without melting it again!!

Si

 

[Arthur Hagen]

What do you mean the chemist didn't have alcohol?

Vin said that the chemists said they didn't have *isopropyl* alcohol
(isopropanol). Alcohol is at least a dozen different things, from methanol
to glycerin.

(Also note that when he said chemist, he almost certainly meant what we call
a drugstore here in the US.)

Do you not have rubbing alcohol in your house? here in the states every
house has a bottle, its used to clean wounds and stuff.

We sure don't have a bottle. Is it mandatory?

What do you use for scraped knee's?

Iodine tinctures, witch hazel, hydrogen peroxide, antibacterial salves and
lotions, or a whole lot of other stuff. Including other alcohols. Using
isopropanol as rubbing alcohol might be a regional thing, because I'm used
to ethanol.

If using denatured ethanol on computer parts, make sure you don't use the
kind that leaves a fatty residue.

Regards,