Beyond 2.4Ghz Mobile Pentium 4-M -- why the price jump?

  • Thread starter Thread starter Guest
  • Start date Start date
G

Guest

I was just looking to buy an upgrade for my Thinkpad's processor,
and noticed that prices for Mobile Pentium 4-M chips are reasonable
until 2.5Ghz, where they jump by around $200 suddenly!

Does anyone know anything about the architecture of these chips
that would justify this massive jump in price over 100Mhz?

Also, what is the difference between "Mobile Pentium 4" and
"Mobile Pentium 4 - M" chips? Intel seems to designate them
differently.

- Tim

--
 
P-M & P4-M are not the same chip.
If your laptop uses P4-M you can't fit a P-M into it.

Also verify how far you can u/g the processor re speed:
o BIOS upgrades will take you quite a way
o However, h/w board revision can be a factor

The best upgrade for a laptop is to go from say a P4-Celeron 2.0Ghz
to a P4-2.66Ghz for example. Within a range, eg, P4-M, you are only
going to get the benefit of a few hundred Mhz. If you find it is the HD
that is slowing you down, consider fitting a Hitachi 7200rpm - your old
HD may well be 4200rpm which is slower on latency & peak transfer.

Re 2.4Ghz v 2.5Ghz, for the 200$ you could buy a faster HD for example.
Depending on your application, that may be more noticeable than the CPU.
 
Dorothy said:
P-M & P4-M are not the same chip.
If your laptop uses P4-M you can't fit a P-M into it.

There was no mention of Pentium M (Dothan can't reach 2.4 GHz yet).

The question was:

What is the difference between "Mobile Pentium 4" and
"Mobile Pentium 4 - M" chips?

Mobile Intel Pentium 4 Processor:
http://intel.com/products/notebook/processors/mobilepentium4/
http://processorfinder.intel.com/scripts/list.asp?ProcFam=1025
http://intel.com/design/mobile/datashts/253028.htm
http://intel.com/design/mobile/datashts/302424.htm

Mobile Intel Pentium 4 Processor - M
http://intel.com/products/notebook/processors/pentium4-m/
http://processorfinder.intel.com/scripts/list.asp?ProcFam=826
http://intel.com/design/mobile/datashts/250686.htm
 
Spammay Blockay said:
I was just looking to buy an upgrade for my Thinkpad's processor,
and noticed that prices for Mobile Pentium 4-M chips are reasonable
until 2.5Ghz, where they jump by around $200 suddenly!

Does anyone know anything about the architecture of these chips
that would justify this massive jump in price over 100Mhz?

Price usually has more to do with supply and demand than what it costs
to do the individual parts, and there's almost always a big premium on
the top-end parts, if you want value you select one or a few steps
below the top-end parts (it's usually obvious where price chart
flattens out).

Sometimes this is caused by low yield (causing low supply and/or high
manufacturing prices), but as often it's due to market segmentation.

The Mobile Pentium 4-M only goes up to 2.6GHz, and that model isn't
even on the "Process Spec Finder"! So, I suspect that in reality the
2.5GHz CPU is the highest in that series that's really available, so
don't expect to find it cheaply until there's at least one and
possibly two MP4-M processors above it (and they have to be available
in some volume too).

Also, what is the difference between "Mobile Pentium 4" and
"Mobile Pentium 4 - M" chips? Intel seems to designate them
differently.

Different power ranges and frequency ranges (and requires different
chipsets too). The frequency range overlap somewhat, and when they do
the Mobile P4 uses a LOT more power than the Mobile P4-M for the same
performance. The Mobile P4 is basically a standard P4 with SpeedStep
support (power savings).

As an example I checked out the MP4 2.4GHz and compared it with MP4-M
2.4Ghz, "Thermal Guideline" for them are 59.8W and 35W respectively.
Quite a difference, even if Thermal Guideline doesn't tell all of the
story, the power reducing features is equally important but is much
harder to measure...

As a comparison the regular P4 2.6GHz has a Thermal Guideline around
59-60W, BUT doesn't have SpeedStep so in practice it will use
significantly more power than the Mobile P4.

The Pentium-M is much harder to compare because we can't use MHz
even as an approximation, but the 2 GHz version should certainly be
much faster and only has a Thermal Guideline of 21W...
SPEC CINT2000 suggests 1.4-1.5GHz P-M might be a more fair comparison,
there are 1.4 GHz TG at 10W(the LV version mentioned below) and 21W...

The Pentium-M 1.1GHz ULV version's TG is 5W, now THAT's low power.

Then there's Mobile Celeron (similar to Mobile P4?) and Celeron-M. It
looks C-M is P-M derived, but rumor has it that it lacks much of the
power saving features that makes P-M so effective, and the spec sheet
does indeed seem to be missing some buzzwords :-) The Celeron-M TG is
similar to the P-M's, but if lacks SpeedStep it's probably closer to a
MP4-M in power usage!

Intel has a lot of information all this on their Webpages, follow the
links if you want more information.
http://www.intel.com/products/notebook/processors/

This is an attempt to summarize the P-M and P4 processors commonly
used in mobile applications (the regular P4 is sometimes used for
portable "workstations", so I've included it).

Pentium-M
http://www.intel.com/products/notebook/processors/pentiumm/
* 1.3-2GHz
* Low power consumption (and the LV/ULV versions are better yet).
* 855 chipset
* Enhanced P6 derived core, significantly faster than the P4-based
cores on a per-clock basis (so MHz can't be compared directly with the
other below).

Mobile Pentium 4-M
http://www.intel.com/products/notebook/processors/pentium4-m/
* 1.4-2.6 GHz
* Medium power consumption
* Mobile 845 chipset
* P4-derived core

Mobile Pentium 4
http://www.intel.com/products/notebook/processors/mobilepentium4/
* 2.4-3.2GHz
* High power consumption
* 852 chipset
* P4-derived core

Pentium 4
http://www.intel.com/products/desktop/processors/pentium4/
* 1.3-3.6GHz
* Very high power consumption
* 925/915/875/865/848/850/845 chipset
* P4 or P4-derived core
* No SpeedStep (power/frequency management functions)
 
P-M & P4-M are not the same chip.
If your laptop uses P4-M you can't fit a P-M into it.

Yes, certainly, this I know. I am talking only about P4-M chips.
Also verify how far you can u/g the processor re speed:
o BIOS upgrades will take you quite a way
o However, h/w board revision can be a factor

The best upgrade for a laptop is to go from say a P4-Celeron 2.0Ghz
to a P4-2.66Ghz for example. Within a range, eg, P4-M, you are only
going to get the benefit of a few hundred Mhz. If you find it is the HD
that is slowing you down, consider fitting a Hitachi 7200rpm - your old
HD may well be 4200rpm which is slower on latency & peak transfer.

Already done (using fastest drives).
Re 2.4Ghz v 2.5Ghz, for the 200$ you could buy a faster HD for example.
Depending on your application, that may be more noticeable than the CPU.

The only thing I can do for this laptop is max out the memory and
upgrade the chip, since everything else is already done. The memory
is decent now (512MB), but I'm bumping it up to 1.25 gig.

- Tim

--
 
A ram(to 512 meg) and/or hard drive(to a 7200 rpm one) upgrade(if your ram is
under 512 meg, and your notebook hard drive is 4400 or 4200 rpm) are
probably much more reasonable upgrades than a cpu upgrade in a notebook.
 
Don't put too much money into the notebook, as you might want to get
an Athlon 64 notebook next year, especially after Windows 64 bit is out.
Well before the end of this year, expect to see a number of different
slim and light Athlon 64 notebooks built around AMD's low power
90 nm mobile Athlon 64 chips.
 
A ram(to 512 meg) and/or hard drive(to a 7200 rpm one) upgrade(if your ram is
under 512 meg, and your notebook hard drive is 4400 or 4200 rpm) are
probably much more reasonable upgrades than a cpu upgrade in a notebook.

I'm upgrading from 512MB to 1.25GB (2GB max on my machine) and
my system drive is already 7200rpm (extra drive is 5400, but hardly
used).

So I was wondering about the CPU in particular... going from 1.8Ghz
to 2.4Ghz should help in multimedia transforms, don't you think?

- Tim

--
 
Don't put too much money into the notebook, as you might want to get
an Athlon 64 notebook next year, especially after Windows 64 bit is out.
Well before the end of this year, expect to see a number of different
slim and light Athlon 64 notebooks built around AMD's low power
90 nm mobile Athlon 64 chips.

That'll have to wait at least 2 years for it to make sense in my budget.
Also, I use my laptop as my main computer, and have another laptop as
my mobile machine (the two machines are a Thinkpad A31 and an X40).

- Tim

--
 
In that case you might want to get a full sized Athlon 64 notebook some time next

year, especially after Windows 64 bit is out, and many great 64 bit applications
start appearing.
 
Spammay said:
I'm upgrading from 512MB to 1.25GB (2GB max on my machine) and
my system drive is already 7200rpm (extra drive is 5400, but hardly
used).

So I was wondering about the CPU in particular... going from 1.8Ghz
to 2.4Ghz should help in multimedia transforms, don't you think?

Probably not that much. A move to 64 bit software will probably help much more.
A 64 bit OS will even help with 32 bit applications. Mobile CPUs also tend to be
expensive. If I were you I would wait until after Windows 64 bit is out, then get
an Athlon 64 notebook. You will probably also be able to get a decent price for
your IBM notebook, as there are corporate types who love and pay high prices for
anything IBM or Intel.
 
Price usually has more to do with supply and demand than what it costs
to do the individual parts, and there's almost always a big premium on
the top-end parts, if you want value you select one or a few steps
below the top-end parts (it's usually obvious where price chart
flattens out).

Yeah, I thought it was something like that. Weird pricing structures.
The Mobile Pentium 4-M only goes up to 2.6GHz, and that model isn't
even on the "Process Spec Finder"! So, I suspect that in reality the
2.5GHz CPU is the highest in that series that's really available, so
don't expect to find it cheaply until there's at least one and
possibly two MP4-M processors above it (and they have to be available
in some volume too).

I noticed that -- I wonder why they would put 2.6Ghz on their site
as the top speed, but only have a spec for 2.5Ghz. Again, weird.
Maybe just because they're phasing this chip out.
This is an attempt to summarize the P-M and P4 processors commonly
used in mobile applications (the regular P4 is sometimes used for
portable "workstations", so I've included it).

Thanks for all the information! Very useful. I eventually
found everything I needed, and saw that the main difference between
the M and non-M versions of the P4 was power consumption.

Now, actually GETTING a P4-M is quite tough... most places, despite showing
it as "in stock", don't actually have it. Eventually ordered it from PC Connection,
and they told me they have to route one from their distributor to a certain
warehouse that ships to my state, for tax reasons. So rather than getting it in
2 days, it might take a week or more. Sucks.

- Tim

--
 
I noticed that -- I wonder why they would put 2.6Ghz on their site
as the top speed, but only have a spec for 2.5Ghz. Again, weird.
Maybe just because they're phasing this chip out.

Paper launches and bragging rights :pPPpp

--
L.Angel: I'm looking for web design work.
If you need basic to med complexity webpages at affordable rates, email me :)
Standard HTML, SHTML, MySQL + PHP or ASP, Javascript.
If you really want, FrontPage & DreamWeaver too.
But keep in mind you pay extra bandwidth for their bloated code
 
There was no mention of Pentium M (Dothan can't reach 2.4 GHz yet).

Indeed - you are right, sorry, my eyesight isn't that great :-)

I'm not sure the processor upgrade is going to yield that much;
o yes it will be quicker in benchmarks
o however, perception in real-world use may be less noticeable

Can you upgrade the memory from 512MB to say 768MB also?
o 512MB is a good size depending on your application & using XP
o However, swap between big apps/files and it isn't actually that big

If you are sat waiting for computations to finish, any CPU u/g helps.
 
Back
Top