"Deep Sleep" mode and pin signals

[lite12]

Hi,

How do you set the computer to "Deep Sleep" mode, if the motherboard does not have many power saving features?

My CPU starts up at a certain voltage and will change the voltage to a higher number after it enters Deep Sleep mode and comes back out of it.

-Lite

 

[I.M.O.G.]

There are two major lower power states you can put your computer into - standby and hibernation.

I believe hibernation is what you are asking for... right click on the desktop and click properties. On the screen saver tab you should have a button near the bottom that says "power". Clicking on that will let you control when your computer goes into lower power consumption modes.

I am not sure what your goal is here, but that is one way you can do what you are trying to do.

Welcome to the forums! Hope you stick around!

 

[NookieN]

Hibernation and standby are features of the operating system and have little to do with the processor.

Deep sleep is a processor state in which the processor remains powered-up and saves all working data, but all core clocks and thus bus clock are stopped. In order to put the processor into deep sleep state it needs to first be put in stop-grant state, then sleep, and finally deep sleep. Getting the processor into these states requires asserting one or more feature pins and then waiting a few microseconds for the PLL to re-lock.

You can find out more about sleep and deep sleep in the P4-M datasheet: http://www.intel.com/design/mobile/datashts/25068607.pdf

Needless to say, if your motherboard and BIOS do not support putting the processor into deep sleep, you won't be able to do it on your own.

 

[I.M.O.G.]

Hibernation and standby are features of the operating system and have little to do with the processor.

Deep sleep is a processor state in which the processor remains powered-up and saves all working data, but all core clocks and thus bus clock are stopped. In order to put the processor into deep sleep state it needs to first be put in stop-grant state, then sleep, and finally deep sleep. Getting the processor into these states requires asserting one or more feature pins and then waiting a few microseconds for the PLL to re-lock.

You can find out more about sleep and deep sleep in the P4-M datasheet: http://www.intel.com/design/mobile/datashts/25068607.pdf

Needless to say, if your motherboard and BIOS do not support putting the processor into deep sleep, you won't be able to do it on your own.

Nice post, very informative.

 

[lite12]

Thanks for the information NookieN, that's just what I'm looking for!

IMOG, you may be right about the standby state. I was able to find some information suggesting that if the motherboard supports S3 state, enabling it will put the CPU in DPSLP when in standby.

I'm testing a modification that should result in an unlocked multiplier for the Pentium 4 533mhz 3.06Ghz Mobile chip. I'm testing an Engineering Sample for now, but theoretically it should work on all chips of this kind. I'm hoping that it will be used on Mobile chips in desktop systems since they can be overclocked upwards of 1.2Ghz without any noticable change in temperatures thanks to the low-k power consumption. On non-mobile chips it may be possible to lower the multiplier (but not raise it) using the same alterations, but I don't have any available for testing.

-Lite

 

[NookieN]

I'm testing a modification that should result in an unlocked multiplier for the Pentium 4 533mhz 3.06Ghz Mobile chip.

It's a nice thought, but it's not going to work the way you think it will. The non-mobile chips only have one multiplier available to them. Even if you can get them into deep sleep (and desktop chips don't officially support deep sleep), you can't change the multiplier. The mobile chips support two multipliers for use with the SpeedStep transition. By default they will boot-up as 12x, but if you put the chip into deep sleep you can change to the higher ratio. However, there are still only those two ratios available.

Also, do not assume that mobile chips have more overclocking potential than non-mobile chips. The silicon is fundamentally the same. The deal with mobile P4 chips is that they are basically cherry-picked desktop chips that run at a lower voltage than the desktop chips. But when you raise the voltage overclock them, they will be using about the same amount of power as their desktop equivalent.

 

[lite12]

On the Engineering Sample I run 4.25Ghz (23x185). The Vcore is 1.2 volts and the temperature rarely exceed 23 degrees. So far no changes in stability.

You're right about only two multipliers being available, but that's what I'm aiming for on the non-ES versions of this chip. If they can overclock as well as the ES then it seems a valuable project for desktop systems.

It's not enough to put it into deepsleep, there needs to be physical modification of the pins to change the GHI# signal to low since neither the OS or the motherboard support SpeedStep. It looks like calling DPSLP or even STPCLK isn't necessary to make the switch, however.

-Lite

 

[I.M.O.G.]

On the Engineering Sample I run 4.25Ghz (23x185). The Vcore is 1.2 volts and the temperature rarely exceed 23 degrees. So far no changes in stability.

You're right about only two multipliers being available, but that's what I'm aiming for on the non-ES versions of this chip. If they can overclock as well as the ES then it seems a valuable project for desktop systems.

It's not enough to put it into deepsleep, there needs to be physical modification of the pins to change the GHI# signal to low since neither the OS or the motherboard support SpeedStep. It looks like calling DPSLP or even STPCLK isn't necessary to make the switch, however.

-Lite

Mind if I ask who you are? (wondering since you have an ES)

 

[NookieN]

It's not enough to put it into deepsleep, there needs to be physical modification of the pins to change the GHI# signal to low since neither the OS or the motherboard support SpeedStep. It looks like calling DPSLP or even STPCLK isn't necessary to make the switch, however.

You still need to put the chip into deepsleep. If you change the bus multiplier while the core clock is running there would probably be data corruption when the PLL attempts to re-lock. In deepsleep the core clock is stopped, so it's safe to change the multiplier since the PLL will have to re-lock anyways. Refer to pages 50 and 96 in the P4M data sheet for more info on this.

 

[lite12]

No one special, IMOG. I'm just fortunate to have access to ES chips.

On a mobile board the open-drain driver allows the GHI# to be modified on the fly using ICH4 southbridge. Aside from using DPSLP... on boot-up the motherboad will set the GHI# signal to high which will predictably set the multiplier to 12x. This means there are two events where GHI# is observed; one is during DPSLP, the other is on reset.

On a desktop system there is no interaction with the GHI#. That works in our favor since on boot-up the system will not reset the GHI# signal. The board is just incapable of setting the GHI# to low which requires a physical modification. Because of this it is permanently set at high (and thus 12x). If the GHI# pin can be modified succesfuly, when the system boots it will accept the new, modified GHI# and set multiplier consistantly to 23x.

Socket 478 has small and delicate pins, so making a modifcation that connects more then one of them without shorting out any of the others is difficult.

What I'm wondering is if putting the system into a suspended state (like S3) will make calls to DPSLP, since it definately stops the CPU.

We'll find out soon if the theory works, hopefully in the near future I will have more information to share.

-Lite