P4M temperature and TDP/watts

J

jameshanley39

In my toshiba satellite pro laptop P4-M 1.9GHz,

it easily gets to the temperature of 50, idling [1]

It appears from the intel processor spec search - processorspecfinder
site that many of the P4-M processors run at TDP of 80W. But all the
(4) P4-M 1.9GHz processors have TDP of 30W

Wouldn't this make my P4-M processor run cooler than the rest?

Yet it still reaches 50+ and the fan goes on.. When idling.

It's a toshiba, well made. I'm not blocking the air vents. I'm running
it on a hard surface. Glass or Wood surface on the table. It's not
trying to blow air under the laptop so tilting the laptop won't help
much.

I'm also wondering if the core 2 duos reach that temp when idling.. I
was hoping that maybe the fan wouldn't go on or would be completely
inaudible - at least when idling.

[1]
irrelevant note about how I measured
(i've monitored load, it is lower when AC adaptor plugged in. I used
speedswitchxp, notebook hardware control, speedfan. They show 0-5% or
< 13% cpu load.. I also tried the software cpuidle putting cpu
"under 100% load" but running that. Perhaps similar to idling I think.
Within about 15 or 20min of idling it reached from 42 to 50. I cooled
it to 42 by setting the fan on/up with speedfan)
 
K

kony

In my toshiba satellite pro laptop P4-M 1.9GHz,

it easily gets to the temperature of 50, idling [1]

Ok, but what is the point?
50C is not too hot.
Idle temp doesn't matter.

Use the laptop in the highest (reasonable) ambient temp you
expect to encounter (nothing unusual, we can't expect use
stranded in a desert, for example) at full load for at least
several minutes continuous. Use that temp to make a
determination of whether it's too hot.

It appears from the intel processor spec search - processorspecfinder
site that many of the P4-M processors run at TDP of 80W. But all the
(4) P4-M 1.9GHz processors have TDP of 30W

Wouldn't this make my P4-M processor run cooler than the rest?

No, it means it produces less heat. "Cooler" running
depends on how effective the cooling subsystem is at
removing the heat, IOW the heatsink and chassis airflow (or
with laptops, air intake and exhaust through the chamber
around the heatsink or heatpipe and fan).


Yet it still reaches 50+ and the fan goes on.. When idling.

Well it is a P4. It is a laptop. Maybe there's some dust
that needs cleaned out, but otherwise nothing seems unusual.

It's a toshiba, well made.

Define well made. If there were a need for it to be cooler,
and it couldn't keep it cool enough, it wouldn't be so well
made would it? However, thus far we don't have any
indication of overheating at 50C, but as mentioned above the
full load temp would have to be taken and considered.

50C is not too hot for any desktop or laptop CPU... but any,
all of them need the full load temp considered, not idle
temp.
I'm not blocking the air vents. I'm running
it on a hard surface. Glass or Wood surface on the table. It's not
trying to blow air under the laptop so tilting the laptop won't help
much.

I'm also wondering if the core 2 duos reach that temp when idling.. I
was hoping that maybe the fan wouldn't go on or would be completely
inaudible - at least when idling.

If the fan doesn't turn on or is slow enough to be
inaudible, that raises CPU temp even more.

Laptops are a tradeoff, allowing a bit higher temp to lower
the noise. There is a limit in how big the fan and heatsink
can be so they deliberately use a lower heat CPU to offset
this, ideally - though some cheaper laptops had used regular
higher heat desktop CPUs, and should be avoided in general
unless it is known to be cool "enough" running.

If you wanted a laptop with lowest noise you could seek
notebook reviews, since the reviewer has enough exposure to
relatively rate the noise, and then with that line of
laptops optimally configured for low noise you would choose
the lowest model CPU that it can run, since within a given
family of CPU, lower speed directly relates to lower heat.

The other factor you didn't mention is whether the temp or
noise level has changed (from when it was newer), but you
must also consider whether the ambient temp is same- since a
higher ambient directly causes higher CPU temp as well.
[1]
irrelevant note about how I measured
(i've monitored load, it is lower when AC adaptor plugged in. I used
speedswitchxp, notebook hardware control, speedfan. They show 0-5% or
< 13% cpu load.. I also tried the software cpuidle putting cpu
"under 100% load" but running that. Perhaps similar to idling I think.
Within about 15 or 20min of idling it reached from 42 to 50. I cooled
it to 42 by setting the fan on/up with speedfan)

Since laptops often are an attempt to squeeze as much as
possible into a tiny space, you will often find that no
matter what CPU is used, they will tend to leverage that
heat level to plan cooling subsystems, IOW if the CPUs it
can use produce less heat it may not have as effective a
cooling subsystem and you will still end up with it running
the fan at load, they assume you want this to save a bit of
space I suppose. Pity they don't take a lesson from "quiet
PC" advocates and use slightly larger fans at lower RPMs,
which would also reduce wear but have only minor weight
increase. I can't recall the last time I cared if the
laptop was 4 mm taller or shorter, actually I would prefer
it thicker so it was more durable (all else equal) and had a
larger battery compartment to allow for higher capacity
cells, longer runtime (if only they would, it seems a rare
luxury to have a laptop run for a mere 8 hours on battery
power).
 
J

jameshanley39

In my toshiba satellite pro laptop P4-M 1.9GHz,
it easily gets to the temperature of 50, idling [1]

Ok, but what is the point?
50C is not too hot.
Idle temp doesn't matter.

It was a statement of fact that is relevant to what I continue to say!

Use the laptop in the highest (reasonable) ambient temp you
expect to encounter (nothing unusual, we can't expect use
stranded in a desert, for example) at full load for at least
several minutes continuous. Use that temp to make a
determination of whether it's too hot.

well, I don't want to argue why I mention the fact of idle temperature
- yet. But I will.
No, it means it produces less heat.
!!!!!!!!!!!!!!

"Cooler" running
depends on how effective the cooling subsystem is at
removing the heat, IOW the heatsink and chassis airflow (or
with laptops, air intake and exhaust through the chamber
around the heatsink or heatpipe and fan).

i'm assuming the "same laptop". Just different processor.
Well it is a P4. It is a laptop. Maybe there's some dust
that needs cleaned out, but otherwise nothing seems unusual.

My point is then, if my P4M 1.9GHz has a TDP of 30W and a temp of 50+
idling. Then would the other P4Ms, the bulk of them, that have TDP
80W, reach a much higher temp?

What kind of temp in the same laptop?

Define well made. If there were a need for it to be cooler,
and it couldn't keep it cool enough, it wouldn't be so well
made would it? However, thus far we don't have any
indication of overheating at 50C, but as mentioned above the
full load temp would have to be taken and considered.

Well, that statment that the toshiba was well made was the first
sentence of a paragraph saying that I am running it on glass or wood.
A hard surface. (So, not a bed). And by well made, I meant that it
doesn't blow fan out the bottom. And the only reason I mentioned
about how I run the laptop and that it is well made, was incase you
suggested xyz(e.g. incase you said "no, it's not too hot, but if
you're running it on your bed, then ). This is a logic issue, i'm
more interested in the technical issue than you rethinking what the
problem is.. I'd like to get the technical addressed, if possible,
first.

50C is not too hot for any desktop or laptop CPU... but any,
all of them need the full load temp considered, not idle
temp.

I'm just asking about idle temp (for whatever reason e.g. at the
moment).

My point is, my P4M CPU 1.9GHz has TDP of 30W, the ones of other GHz,
have TDP of 90W.

So, in the same laptop, do you think the others would need a more
powerful fan / would likely be noisier machine.
If the fan doesn't turn on or is slow enough to be
inaudible, that raises CPU temp even more.

I'm not asking that.. Obviously a fan that doesn't turn on will raise
CPU temp.

My point is that I recall that a core 2 duo has a TDP of about 30W..
So in the same toshiba laptop case as mine, i.e. the same cooling
system that I have, do you think it'd probably idle at around 50 too?

Do you think that other P4Ms (80W ones) in that laptop would idle at
much higher temperatures at the fan speed that I have.. (my processor
is a 30W P4M)

Most people say that a P4M is not really a mobile CPU, that the mobile
thing is a gimmick, that they consume as much power as a P4.

Well this doesn't appear to be the case if the TDP is 30W. The 1.9GHz
P4Ms have a TDP of 30W

Laptops are a tradeoff, allowing a bit higher temp to lower
the noise. There is a limit in how big the fan and heatsink
can be so they deliberately use a lower heat CPU to offset
this, ideally - though some cheaper laptops had used regular
higher heat desktop CPUs, and should be avoided in general
unless it is known to be cool "enough" running.

If you wanted a laptop with lowest noise you could seek
notebook reviews, since the reviewer has enough exposure to
relatively rate the noise, and then with that line of
laptops optimally configured for low noise you would choose
the lowest model CPU that it can run, since within a given
family of CPU, lower speed directly relates to lower heat.

I'm not asking for advice like that on how to choose a quiet laptop.
It's subjective. The silent ones I've noticed have been by chance..
I'd have to try a laptop before buying it.. Or perhaps somehow get
more technical with laptops and cooling and modify the heatsink
somehow, but that's really not the issue..
The other factor you didn't mention is whether the temp or
noise level has changed (from when it was newer), but you
must also consider whether the ambient temp is same- since a
higher ambient directly causes higher CPU temp as well.


irrelevant to me. I'm not modifying the central heating to keep my
laptop a few degrees cooler. Whatever the ambient temperature is is
what it is, it's a given. Yes, I know it prob affects it - to some
extent.
[1]
irrelevant note about how I measured
(i've monitored load, it is lower when AC adaptor plugged in. I used
speedswitchxp, notebook hardware control, speedfan. They show 0-5% or
< 13% cpu load.. I also tried the software cpuidle putting cpu
"under 100% load" but running that. Perhaps similar to idling I think.
Within about 15 or 20min of idling it reached from 42 to 50. I cooled
it to 42 by setting the fan on/up with speedfan)

Since laptops often are an attempt to squeeze as much as
possible into a tiny space, you will often find that no
matter what CPU is used, they will tend to leverage that
heat level to plan cooling subsystems, IOW if the CPUs it
can use produce less heat it may not have as effective a
cooling subsystem and you will still end up with it running
the fan at load, they assume you want this to save a bit of
space I suppose. Pity they don't take a lesson from "quiet
PC" advocates and use slightly larger fans at lower RPMs,
which would also reduce wear but have only minor weight
increase. I can't recall the last time I cared if the
laptop was 4 mm taller or shorter, actually I would prefer
it thicker so it was more durable (all else equal) and had a
larger battery compartment to allow for higher capacity
cells, longer runtime (if only they would, it seems a rare
luxury to have a laptop run for a mere 8 hours on battery
power).

A friend had an IBM X22 , there are many subtypes. But his one had a
metal surface, it got EXTREMELY hot, too hot to touch even.. I don't
know what his temperatures were like but the laptop seemed to last.
It was dead silent.. I was googling about cool surface for laptop,
and found a product "lapinator" http://www.lapinator.com/ , which, if
no fan, would have made a beautiful silent solution with that laptop.

The main point in my post is a technical one
Comparison between temp of my TDP 30W P4M 1.9GHz , and other P4Ms, TDP
80W. (assuming same fan, same laptop case even of couse)

And comparing AGAIN, same laptop case, same ambient temperature..
*OBVIOUSLY*.. The core2duo with the my P4M, I think the TDP are
similar.

Another reason why I say assume same case, is because I think my
toshiba is well made. Toshiba usually are, If I knew of a better case
i'd look into laptops with a better design.

I actually think that the fan is off when the temp is below 50. If
that's possible.. I can't hear it at all.. When I tell speedfan to
make the fan higher, it's completely inaudible then once speedfan is
set to 50% fan speed, the fan becomes very audible. The fan speed
doesn't step up.

My hope is that if it were true that the P4M runs HOT then , given
that it prob idles at 52 or so, or gets to that easily.. Then a
processor that runs cooler will obviously idle lower. If it were true
that the P4M doesn't even deserve to be called a mobile processor,
that the core2duo is much cooler, then I'd have more luck with a
core2duo (obviously i'd wait till the price drops though!).. However,
since my P4M is 30W, I'm thinking maybe it is releatively cool and
does deserve to be called mobile. Though I then wonder if other P4Ms
at 80W require much louder fans. (I know that 40s is good for idling
on a P4 northwood, and perhaps 50s on a P4 prescott were an uninformed
person to get one. I don't know what a typical temp is for a P4M like
mine is compared to the other wattage)


I'm going round in BIG circles here. You avoided the question by
trying to rethink and guess at what my 'problem' was! It's a technical
question. Your telling me what you're telling me is very good - though
it's not new to me - and besides, I'd rather it was after the
technical question is addressed.
 
K

kony

In my toshiba satellite pro laptop P4-M 1.9GHz,
it easily gets to the temperature of 50, idling [1]

Ok, but what is the point?
50C is not too hot.
Idle temp doesn't matter.

It was a statement of fact that is relevant to what I continue to say!

Ok, but we can't really use the idle temp as a gauge of
anything since laptops are designed to let the CPU heat up
to this point or beyond, before turning fan on or up.

Anyway, most of my reply is just a rehash to skip down to
the end, last 4 paragraphs or so for the condensed answer.


well, I don't want to argue why I mention the fact of idle temperature
- yet. But I will.


!!!!!!!!!!!!!!


Which doesn't mean anything. I can take a 11W underclocked
Celeron @ 600-odd MHz and just sitting there with a passive
heatsink w/o fan it will get up to 50C, no matter how power
miserly the CPU is it will heat up until the trip point for
the thermal sensor circuit turns the fan on.



My point is then, if my P4M 1.9GHz has a TDP of 30W and a temp of 50+
idling. Then would the other P4Ms, the bulk of them, that have TDP
80W, reach a much higher temp?

In the same laptop, no. The fan would just turn on sooner.
If the laptop isn't engineered well enough to deal with the
desktop chip's heat levels then it is possible that even
with fan on at full speed the upper temp would be higher at
a partial-to-full load, almost certainly it would at full
load but you weren't talking about full load.

I'm just asking about idle temp (for whatever reason e.g. at the
moment).

My point is, my P4M CPU 1.9GHz has TDP of 30W, the ones of other GHz,
have TDP of 90W.

So, in the same laptop, do you think the others would need a more
powerful fan / would likely be noisier machine.

Yes, absolutely one of the two, either fan turns on sooner
or it gets hotter. For this reason I think a P4 of any type
is not so well suited for laptops, but the desktop versions
would be particularly bad.


My point is that I recall that a core 2 duo has a TDP of about 30W..
So in the same toshiba laptop case as mine, i.e. the same cooling
system that I have, do you think it'd probably idle at around 50 too?

No I would expect it slightly cooler since TDP is the upper
limit not an idle power consumption.


Do you think that other P4Ms (80W ones) in that laptop would idle at
much higher temperatures at the fan speed that I have.. (my processor
is a 30W P4M)
yes



Most people say that a P4M is not really a mobile CPU, that the mobile
thing is a gimmick, that they consume as much power as a P4.

Check the spec sheet. Generally one benefit is the P4M
should have lower voltage per same clock speed, be tested to
do that as well as remain stable at even further voltage
reduction as speed is scaled lower by the laptop. The
voltage tolerance alone is a substantial benefit in heat
reduction.


I'm not asking for advice like that on how to choose a quiet laptop.
It's subjective. The silent ones I've noticed have been by chance..
I'd have to try a laptop before buying it.. Or perhaps somehow get
more technical with laptops and cooling and modify the heatsink
somehow, but that's really not the issue..

I still don't see what the issue is, as it is really as
straightforward as it seems that a higher TDP CPU will have
higher heat for the cooling subsystem to be rid of at load,
but at idle it depends on voltage, core design, and actual
speed. If you are letting it idle, it's not running
demanding jobs, the obvious solution for any mobile is to
reduce it's speed (which if working properly, will reduce
voltage too).



A friend had an IBM X22 , there are many subtypes. But his one had a
metal surface, it got EXTREMELY hot, too hot to touch even.. I don't
know what his temperatures were like but the laptop seemed to last.
It was dead silent.. I was googling about cool surface for laptop,
and found a product "lapinator" http://www.lapinator.com/ , which, if
no fan, would have made a beautiful silent solution with that laptop.

I've no experience with the product, but yes it might... any
laptop that integrades a heat *spreader* on the bottom will
have that alternate path to conduct heat.

The main point in my post is a technical one
Comparison between temp of my TDP 30W P4M 1.9GHz , and other P4Ms, TDP
80W. (assuming same fan, same laptop case even of couse)

And comparing AGAIN, same laptop case, same ambient temperature..
*OBVIOUSLY*.. The core2duo with the my P4M, I think the TDP are
similar.

Ok, but as I'd mentioned right at the start, you cite TDP
but not full load temps so the two figures aren't directly
applicable to your scenario. We could make assumptions from
them, generally predict one would be hotter at idle but a
closer look at the specs for each would help more, like the
voltage difference mentioned above.


Another reason why I say assume same case, is because I think my
toshiba is well made. Toshiba usually are, If I knew of a better case
i'd look into laptops with a better design.

It could be quite well made, but the laws of physics still
apply, that even a horribly made laptop could, if it allowed
for a better heatsink and passive ventilation system, run to
a higher heat load before the fans turns on or up.
I actually think that the fan is off when the temp is below 50. If
that's possible.. I can't hear it at all.. When I tell speedfan to
make the fan higher, it's completely inaudible then once speedfan is
set to 50% fan speed, the fan becomes very audible. The fan speed
doesn't step up.

My hope is that if it were true that the P4M runs HOT then , given
that it prob idles at 52 or so, or gets to that easily.. Then a
processor that runs cooler will obviously idle lower.
If it were true
that the P4M doesn't even deserve to be called a mobile processor,
that the core2duo is much cooler, then I'd have more luck with a
core2duo (obviously i'd wait till the price drops though!)..

P4M deserves to be called mobile as it is a contrast versus
the non-mobile, not a statement about how suitable it would
be in a laptop compared to newer CPUs. We already knew the
P4 architecture was high heat:performance ratio even at
idle.

I'm going round in BIG circles here. You avoided the question by
trying to rethink and guess at what my 'problem' was!

Your preface information seemed to imply you misunderstood
the situation. I'm thinking the question you wanted to ask
was;

"If I switch a P4M to a Core2Duo in the same laptop, will
the fan run less often or stay off at idle in a 25C room
environment if the casing vents aren't blocked".

The answer there is that it depends on the actual passive
C/W effectiveness of the heatsink when the fan isn't on, and
if the fan runs at multiple speeds when you aren't try to do
it yourself, whether it would remain at the lower speed
(presumably a less offensive sound level) during typical
working loads. Since we don't have these figures for the
cooling system, we can't conclude whether it would allow
keeping the fan off or not at any particular processor
power->heat level.

What we can still do is compare the other thermal parameters
Intel has released for the CPUs themselves, for example here
is a Core2Duo Mobile datasheet, (if it goes away at some
point just navigate through Intel's site to find again, or
to find an updated version though this one is new).

http://download.intel.com/design/mobile/datashts/31407803.pdf

Section 5.1 / pg.74+, you will have to differentiate between
the LV or ULV (ultra low voltage) alternatives, I've no idea
what your laptop can use. That gets down to 5.2/3.1W
respectively.

Now to compare, take the P4M datasheet you're getting that
30W figure from, but instead compare the idle Halt, Stop
Grant figure.
 

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