Mobile Intel Pentium 4 + ICH5

Mobile Intel Pentium 4 + ICH5

[Ronald van der Meer]

Hi,

I have a laptop with an Mobile Intel(R) Pentium(R) 4 cpu and a 82801EB
ICH5 southbridge.
I can use the p4-clockmod driver, but it doesn't seem to save any power
because it only changes the frequency and doesn't do voltage scaling.
The speedstep-ich driver only seems to support ICH2, 3 and 4 but not 5.
Is voltage scaling speedstep possible for this laptop?

cheers,

Ronald

Re: Mobile Intel Pentium 4 + ICH5

[Bas Mevissen]

Ronald van der Meer wrote:
> Hi,
> 
> I have a laptop with an Mobile Intel(R) Pentium(R) 4 cpu and a 82801EB
> ICH5 southbridge.
> I can use the p4-clockmod driver, but it doesn't seem to save any power
> because it only changes the frequency and doesn't do voltage scaling.
> The speedstep-ich driver only seems to support ICH2, 3 and 4 but not 5.
> Is voltage scaling speedstep possible for this laptop?
> 

Hi Ronald,

The p4-clockmod driver only modulates the CPU-clock. That means that the 
clock is running like this: 1111000000001111000000001111 (1=on, 0=off).

Because the clock is running at max CPU speed when on, the voltage 
cannot be lowered. In theory, the voltage could be dropped when the 
clock is off. But because it takes some time before the voltage 
stabilises again, that would mean that the modulation frequency should 
become so slow that it would be very noticable (e.g. jerky mouse movement).

So what you need is speedstep-ich. That driver can both change CPU 
frequency and CPU voltage. But you say it does not support ICH5. Did you 
try it already or did you only read the documentation?

BTW. What labtop do you have?

Regards,

Bas.

Re: Mobile Intel Pentium 4 + ICH5

[Ronald van der Meer]

Hi,

> The p4-clockmod driver only modulates the CPU-clock. That means that the 
> clock is running like this: 1111000000001111000000001111 (1=on, 0=off).
> 
> Because the clock is running at max CPU speed when on, the voltage 
> cannot be lowered. In theory, the voltage could be dropped when the 
> clock is off. But because it takes some time before the voltage 
> stabilises again, that would mean that the modulation frequency should 
> become so slow that it would be very noticable (e.g. jerky mouse movement).

Thanx for the info on the p4-clockmod driver. It seems like a pretty
much useless cpu-feature to me since it doesn't save any power. It just
slows stuff down, which maybe even costs more battery-power per task
simply because the task will take longer to finish. If this is true
isn't it even misleading for this driver to be in the power-management
part of the kernel because this implies it saves power? A warning at
least seems very appropriate to me.

> So what you need is speedstep-ich. That driver can both change CPU 
> frequency and CPU voltage. But you say it does not support ICH5. Did you 
> try it already or did you only read the documentation?

I tried a rather old patch (20031203) which didn't work. I checked the
current source of the speedstep-ich driver. The function
speedstep_detect_chipset in line 186 of speedstep-ich.c doesn't seem to
check for my southbridge. This matches what is in the documentation. So
trying again seems pretty useless.

So does anybody have any clue about speedstep support with the ICH5 ?

> BTW. What labtop do you have?

It's a Medion MD40100, for more info on it's internals check
http://home.conceptsfa.nl/~revdmeer/md40100/

Ronald

Re: Mobile Intel Pentium 4 + ICH5

[Bruno Ducrot]

On Thu, Feb 12, 2004 at 07:30:12PM +0100, Ronald van der Meer wrote:
> Hi,
> 
> > BTW. What labtop do you have?
> 
> It's a Medion MD40100, for more info on it's internals check
> http://home.conceptsfa.nl/~revdmeer/md40100/
> 

Could you please send 'lspci -n' ?
BTW, I don't see an ICH-5 mobile version on intel site yet ?

-- 
Bruno Ducrot

--  Which is worse:  ignorance or apathy?
--  Don't know.  Don't care.

Re: Mobile Intel Pentium 4 + ICH5

[Ronald van der Meer]

On Fri, 2004-02-13 at 01:15, Bruno Ducrot wrote:
> On Thu, Feb 12, 2004 at 07:30:12PM +0100, Ronald van der Meer wrote:
> > Hi,
> > 
> > > BTW. What labtop do you have?
> > 
> > It's a Medion MD40100, for more info on it's internals check
> > http://home.conceptsfa.nl/~revdmeer/md40100/
> > 
> 
> Could you please send 'lspci -n' ?

00:00.0 Class 0600: 8086:2570 (rev 02)
00:01.0 Class 0604: 8086:2571 (rev 02)
00:1d.0 Class 0c03: 8086:24d2 (rev 02)
00:1d.1 Class 0c03: 8086:24d4 (rev 02)
00:1d.2 Class 0c03: 8086:24d7 (rev 02)
00:1d.3 Class 0c03: 8086:24de (rev 02)
00:1d.7 Class 0c03: 8086:24dd (rev 02)
00:1e.0 Class 0604: 8086:244e (rev c2)
00:1f.0 Class 0601: 8086:24d0 (rev 02)
00:1f.1 Class 0101: 8086:24db (rev 02)
00:1f.3 Class 0c05: 8086:24d3 (rev 02)
00:1f.5 Class 0401: 8086:24d5 (rev 02)
00:1f.6 Class 0703: 8086:24d6 (rev 02)
01:00.0 Class 0300: 10de:032c (rev a1)
03:04.0 Class 0607: 104c:ac8e
03:04.1 Class 0607: 104c:ac8e
03:04.2 Class 0c00: 104c:802e
03:04.3 Class 0180: 104c:ac8f
03:05.0 Class 0200: 10ec:8139 (rev 10)
03:06.0 Class 0280: 1260:3890 (rev 01)

> BTW, I don't see an ICH-5 mobile version on intel site yet ?

I don't think it's a special mobile version. Probably this one:
http://developer.intel.com/design/chipsets/datashts/252523.htm

would this totally rule out the using speedstep which the CPU does seem
to support? 

Re: Mobile Intel Pentium 4 + ICH5

[Dominik Brodowski]

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On Fri, Feb 13, 2004 at 07:10:25AM +0100, Ronald van der Meer wrote:
> I don't think it's a special mobile version. Probably this one:
> http://developer.intel.com/design/chipsets/datashts/252523.htm
> 
> would this totally rule out the using speedstep which the CPU does seem
> to support? 

Unfortunately, it does seem so. The ICH-5 is a desktop version and does
not include the special registers necessary for speedstep control.

Does the acpi cpufreq-driver (latest(!) 2.6.) work?

	Dominik

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Re: Mobile Intel Pentium 4 + ICH5

[Bruno Ducrot]

On Fri, Feb 13, 2004 at 10:26:44AM +0100, Dominik Brodowski wrote:
> On Fri, Feb 13, 2004 at 07:10:25AM +0100, Ronald van der Meer wrote:
> > I don't think it's a special mobile version. Probably this one:
> > http://developer.intel.com/design/chipsets/datashts/252523.htm
> > 
> > would this totally rule out the using speedstep which the CPU does seem
> > to support? 
> 
> Unfortunately, it does seem so. The ICH-5 is a desktop version and does
> not include the special registers necessary for speedstep control.

Indeed.  Those registers are 'reserved' as for others non-mobile ICH
version.  I really don't know what will happens if the OP force detection.

-- 
Bruno Ducrot

--  Which is worse:  ignorance or apathy?
--  Don't know.  Don't care.

Re: Mobile Intel Pentium 4 + ICH5

[Ronald van der Meer]

On Fri, 2004-02-13 at 10:26, Dominik Brodowski wrote:
> On Fri, Feb 13, 2004 at 07:10:25AM +0100, Ronald van der Meer wrote:
> > I don't think it's a special mobile version. Probably this one:
> > http://developer.intel.com/design/chipsets/datashts/252523.htm
> > 
> > would this totally rule out the using speedstep which the CPU does seem
> > to support? 
> 
> Unfortunately, it does seem so. The ICH-5 is a desktop version and does
> not include the special registers necessary for speedstep control.

What registers would be required for the Intel Mobile Pentium 4 to do
it's speedstep thing?

Reading through it's datasheet
(http://www.intel.com/design/mobile/datashts/253028.htm)
I couldn't find any reference to southbridges or it's registers. It
seems to require significantly less signals from outside than older
intel mobile procs. For example:

The processor determines it's own voltage by driving it's VID[4:0] pins
(table 3, page 15 of datasheet) to a Voltage Regulation Module (VRM).
So this processor doesn't need a mobile ICH and an external latch (as
shown in the block diagram figure 5-14, on page 155 of the ICH4-M
datasheet) to provide this functionality.

The datasheet btw doesn't talk about speedstep, but about enhanced
speedstep. The VID[4:0] signal driving described above seem like one of
the enhancements to me, anybody know any others ?

Infact the way I read the datasheet all it takes to do speedstepping is:

Switch to max-performance mode : Set GHI# pin low, put processor into
Deep Sleep state, return to normal state.
Switch to battery optimized mode : Set GHI# pin high, put processor into
Deep Sleep state, return to normal state.

This raises 2 questions:

Is changing the processors state to "Deep Sleep" and back possible in
linux?
To what is the processors GHI# pin connected? 

I realise all this research may turn out to be pointless, but I would
like to be 100% certain if speedstepping is possible or not. Just saying
'the ICH5 is not a special mobile version so speedstepping is not
possible' seems too easy to me.

> Does the acpi cpufreq-driver (latest(!) 2.6.) work?

I'm afraid it will not because 'cat
/proc/acpi/processor/CPU/performance' always showed '<not supported>' on
the kernels I tried. But next time I try a recent 2.6 kernel I'll try. 

Ronald

Re: Mobile Intel Pentium 4 + ICH5

[Bruno Ducrot]

On Sun, Feb 15, 2004 at 06:03:12PM +0100, Ronald van der Meer wrote:
> On Fri, 2004-02-13 at 10:26, Dominik Brodowski wrote:
> > On Fri, Feb 13, 2004 at 07:10:25AM +0100, Ronald van der Meer wrote:
> > > I don't think it's a special mobile version. Probably this one:
> > > http://developer.intel.com/design/chipsets/datashts/252523.htm
> > > 
> > > would this totally rule out the using speedstep which the CPU does seem
> > > to support? 
> > 
> > Unfortunately, it does seem so. The ICH-5 is a desktop version and does
> > not include the special registers necessary for speedstep control.
> 
> What registers would be required for the Intel Mobile Pentium 4 to do
> it's speedstep thing?
> 
> Reading through it's datasheet
> (http://www.intel.com/design/mobile/datashts/253028.htm)
> I couldn't find any reference to southbridges or it's registers. It
> seems to require significantly less signals from outside than older
> intel mobile procs. For example:

Normal, that's under NDA, mostly, apart the register associated to the
ICH?m southbridge.

> The processor determines it's own voltage by driving it's VID[4:0] pins
> (table 3, page 15 of datasheet) to a Voltage Regulation Module (VRM).
> So this processor doesn't need a mobile ICH and an external latch (as
> shown in the block diagram figure 5-14, on page 155 of the ICH4-M
> datasheet) to provide this functionality.

You program the VID output via the VRM module which is under NDA, and
actualy I don't know if that is correct :)

> The datasheet btw doesn't talk about speedstep, but about enhanced
> speedstep. The VID[4:0] signal driving described above seem like one of
> the enhancements to me, anybody know any others ?

No.  That's how it work back to pentium III (coppermine, speedstep
capable).

> Infact the way I read the datasheet all it takes to do speedstepping is:
> 
> Switch to max-performance mode : Set GHI# pin low, put processor into
> Deep Sleep state, return to normal state.
> Switch to battery optimized mode : Set GHI# pin high, put processor into
> Deep Sleep state, return to normal state.

You toggle the GHI# pin via an enhanced propritary ASIC for which you
will not get specification from Intel unless you sign a NDA.

> This raises 2 questions:
> 
> Is changing the processors state to "Deep Sleep" and back possible in
> linux?
> To what is the processors GHI# pin connected? 

To a propritary ASIC already mentionned that you will find no reference
from Intel litterature.

> I realise all this research may turn out to be pointless, but I would
> like to be 100% certain if speedstepping is possible or not. Just saying
> 'the ICH5 is not a special mobile version so speedstepping is not
> possible' seems too easy to me.

No.  That's the truth unfortunately.  All Speedstep capable processor
(apart perhaps the Banias on centrino platform) need at least:
A mobile VRM,
A propritary ASIC,
A northbridge which will connected somehow to that ASIC,
A southbridge, that one integrated a part of the state machine
associated to SpeedStep technology (the trigger part, mostly).

It was possible, back to PIII, to have a southbridge that do not
incorporate a part of the state machine associated to speedstep, 
but then it was necessary to reserve a GPO and a GPI for speedstep.

It is possible after all that it is still the case when the southbridge
is not a mobile version, but frankly, I doubt that is the case.
To be sure, you may try to dump the GPO associated when you boot on AC,
then on Battery, and see if that make a difference, like it's done
for the PIIX4 IO version.

Cheers,

-- 
Bruno Ducrot

--  Which is worse:  ignorance or apathy?
--  Don't know.  Don't care.

Re: Mobile Intel Pentium 4 + ICH5

[Dominik Brodowski]

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On Thu, Feb 12, 2004 at 07:30:12PM +0100, Ronald van der Meer wrote:
> Thanx for the info on the p4-clockmod driver. It seems like a pretty
> much useless cpu-feature to me since it doesn't save any power. It just
> slows stuff down, which maybe even costs more battery-power per task
> simply because the task will take longer to finish. If this is true
> isn't it even misleading for this driver to be in the power-management
> part of the kernel because this implies it saves power? A warning at
> least seems very appropriate to me.

On systems where no "idle" states C2 or C3 are offered, the p4-clockmod
driver can save (some, not much) power, AFAIK. However, for P4-M or other
advanced mobile processors, it is more or less useless. Because of this, a
warning was added a couple of days ago to the 2.6. p4-clockmod driver
stating:

                printk(KERN_DEBUG PFX "Warning: Pentium 4-M detected. The speedstep-ich or acpi cpufreq \n");
                printk(KERN_DEBUG PFX "modules offers voltage scaling in addition of frequency scaling. You\n");
                printk(KERN_DEBUG PFX "should use either one instead of p4-clockmod, if possible.\n");
 
or
                printk(KERN_DEBUG PFX "Warning: Pentium M detected. The speedstep_centrino module\n");
                printk(KERN_DEBUG PFX "offers voltage scaling in addition of frequency scaling. You\n");
                printk(KERN_DEBUG PFX "should use that instead of p4-clockmod, if possible.\n");
 

	Dominik

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RE: Mobile Intel Pentium 4 + ICH5

[Grover, Andrew]

> > It's a Medion MD40100, for more info on it's internals check
> > http://home.conceptsfa.nl/~revdmeer/md40100/
> > 
> 
> Could you please send 'lspci -n' ?
> BTW, I don't see an ICH-5 mobile version on intel site yet ?

ICH5 doesn't come in a mobile version. ICH6 will.

-- Andy

Re: Mobile Intel Pentium 4 + ICH5

[Bruno Ducrot]

On Fri, Feb 13, 2004 at 01:32:15PM -0800, Grover, Andrew wrote:
> > > It's a Medion MD40100, for more info on it's internals check
> > > http://home.conceptsfa.nl/~revdmeer/md40100/
> > > 
> > 
> > Could you please send 'lspci -n' ?
> > BTW, I don't see an ICH-5 mobile version on intel site yet ?
> 
> ICH5 doesn't come in a mobile version. ICH6 will.
> 

Yes, that what I suspected unfortunately, and I hoped that the OP
actually made a mistake (that's why I requested from him a lspci -n).

So far, it seems that there are dummy OEMs that ship that chip in their
mobile products :(

-- 
Bruno Ducrot

--  Which is worse:  ignorance or apathy?
--  Don't know.  Don't care.

Re: Mobile Intel Pentium 4 + ICH5

[Bas Mevissen]

Grover, Andrew wrote:

>>>
> ICH5 doesn't come in a mobile version. ICH6 will.
> 

Are you also sure that there is no speedstep possible with it?

Bas.

Re: Mobile Intel Pentium 4 + ICH5

[Bruno Ducrot]

On Mon, Feb 16, 2004 at 11:13:48AM +0100, Bas Mevissen wrote:
> Grover, Andrew wrote:
> 
> >>>
> >ICH5 doesn't come in a mobile version. ICH6 will.
> >
> 
> Are you also sure that there is no speedstep possible with it?
> 

Andrew do not have the right to answer you, or he may loose his job.

-- 
Bruno Ducrot

--  Which is worse:  ignorance or apathy?
--  Don't know.  Don't care.

Re: Mobile Intel Pentium 4 + ICH5

[Bas Mevissen]

Bruno Ducrot wrote:

> On Mon, Feb 16, 2004 at 11:13:48AM +0100, Bas Mevissen wrote:
> 
>>Grover, Andrew wrote:
>>
>>
>>>ICH5 doesn't come in a mobile version. ICH6 will.
>>>
>>
>>Are you also sure that there is no speedstep possible with it?
>>
> Andrew do not have the right to answer you, or he may loose his job.
> 

Oh, that's not the kind of information I was looking for. I was 
wondering if an ICH5 with some (custom) external logic would be able to 
speedstep.

What I suspect is that Medion used the cheaper(?) ICH5 in their 
notebooks together with a speedstep capable CPU. For speedstepping, they 
might have build their own logic or used something more or less common.

What I wanted to know from Andrew is if this is possible at all, without 
asking him to disclose something that he is not allowed to tell, of course.

Regards,

Bas.

Re: Mobile Intel Pentium 4 + ICH5

[Bruno Ducrot]

On Mon, Feb 16, 2004 at 02:45:37PM +0100, Bas Mevissen wrote:
> Bruno Ducrot wrote:
> 
> >On Mon, Feb 16, 2004 at 11:13:48AM +0100, Bas Mevissen wrote:
> >
> >>Grover, Andrew wrote:
> >>
> >>
> >>>ICH5 doesn't come in a mobile version. ICH6 will.
> >>>
> >>
> >>Are you also sure that there is no speedstep possible with it?
> >>
> >Andrew do not have the right to answer you, or he may loose his job.
> >
> 
> Oh, that's not the kind of information I was looking for. I was 
> wondering if an ICH5 with some (custom) external logic would be able to 
> speedstep.

That is possible, but I doubt that is the case for the ICH5.
I can be wrong of course.  After all, there were no PIIX4 with special
requirement for speedstep capable processor.  Look at my lastest answer
to the OP.

> What I suspect is that Medion used the cheaper(?) ICH5 in their 
> notebooks together with a speedstep capable CPU. For speedstepping, they 
> might have build their own logic or used something more or less common.

Don't buy medion, then.  I think that you should use the ICH5 only with
the centrino, not the P4, if you are designing a laptop.  But still, I
may be wrong.

> What I wanted to know from Andrew is if this is possible at all, without 
> asking him to disclose something that he is not allowed to tell, of course.

Yes, perhaps, but if Andrew do not answer, don't take offense, that's the
game, after all.

-- 
Bruno Ducrot

--  Which is worse:  ignorance or apathy?
--  Don't know.  Don't care.