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System Sleep ?s

Message #1 - Posted 2004/05/05 - Norm

Trying to understand the "sleep" function in Energy Saver.

Can I connect to a computer that is in Sleep mode?

Can a program launch at a set time when a computer is in Sleep mode?

If Powerbook is powered by Power Adapter not battery is there any benefit to Sleep the computer?

Background: I'm able to access my wife's Powerbook both to do a Retrospect backup and connect from my Mac even though her Mac's screen is dark and the energy settings are set to sleep the system and display at same time after10 minutes. So by that I'm assuming her Powerbook is in Sleep mode when screen dark. But I didn't think it should respond to Retrospect or to attempts to connect from another computer when in Sleep. So I'm confused.

Not sure if this is an OS or Powerbook question.

Thanks for any education on this.

Please send email to: nwhiii at yahoo dot com

Message #2 - Posted 2004/05/05 - Thomas Reed

Previously, Norm wrote:

Can I connect to a computer that is in Sleep mode?

Depends on the hardware. I think that some newer hardware will allow the machine to wake up if someone tries to connect to it over the network.

Can a program launch at a set time when a computer is in Sleep mode?

Again, depends on the hardware. Some hardware lets you wake the computer at scheduled times. But nothing goes on *during* sleep, so there's no possibility for having a program launch and do something while the computer is sleeping.

If Powerbook is powered by Power Adapter not battery is there any benefit to Sleep the computer?

Reduced power consumption. That's about it.

Background: I'm able to access my wife's Powerbook both to do a Retrospect backup and connect from my Mac even though her Mac's screen is dark and the energy settings are set to sleep the system and display at same time after10 minutes. So by that I'm assuming her Powerbook is in Sleep mode when screen dark.

Not necessarily. The screen can be set to dim before the system goes to sleep. And if you've got new enough hardware, it's possible that your machine's Retrospect network query wakes hers up, though I'm not sure about that.

Message #3 - Posted 2004/05/05 - clvrmnky

On 05/05/2004 12:36 PM, Norm wrote:

Trying to understand the "sleep" function in Energy Saver.

Can I connect to a computer that is in Sleep mode?

If your hardware supports "wake on LAN", you can find applications that can send the "magic packet" to the MAC address to wake it up. While in hibernation, Mac will not respond to normal network traffic, and it's IP address will be non responsive.

Once woken up, the Mac will restart the various network protocols and daemons that maintain them, and regular traffic will be allowed. Note that network traffic does not keep a Mac from going back to sleep once the sleep timer has elapsed again.

Can a program launch at a set time when a computer is in Sleep mode?

I've wondered this myself. There are settings to have the computer "turn on" at a specific time which implies that this panel and the work it does can talk to the OpenBoot or power management unit directly. This is kind of cool, if it works.

Would be easy to test. Set it to wake up at X O'clock. Force it to go into hibernation mode at 5 minutes to. Test by trying to "ping" the box while it's in hibernation. If you get a response back, it ain't sleeping (deeply). Wait to see if it wakes up at X O'clock. Rinse. Repeat.

If Powerbook is powered by Power Adapter not battery is there any benefit to Sleep the computer?

*shrug* Depends on what you mean by "benefit". There might be some

savings on energy (when not running by battery, I think most G3/G4 based laptops consume a goodly amount of power) and wear-and-tear on anything that makes heat.

Background: I'm able to access my wife's Powerbook both to do a Retrospect backup and connect from my Mac even though her Mac's screen is dark and the energy settings are set to sleep the system and display at same time after10 minutes. So by that I'm assuming her Powerbook is in Sleep mode when screen dark. But I didn't think it should respond to Retrospect or to attempts to connect from another computer when in Sleep. So I'm confused.

It's not in true hibernation mode, unless Retrospect is smart enough to wake the PBook up before it does what it has to do.

Is the PowerBook in true hibernation mode? Is the power light on the front throbbing? Can you "ping" or "ssh" to the PowerBook when it appears to be asleep? If so, it is not in hibernation, but in a simpler power-save mode where the screen darkens and disc spins down. The network hardware and CPU are still being fully powered.

cm

Message #4 - Posted 2004/05/05 - Stefan Monnier

Is the PowerBook in true hibernation mode?

Just for the record: I got confusd by your post.
In my world "hibernation" is different from "suspend": it stands for "suspend to disk" (which doesn't exist on my PowerBook, BTW) which means that your RAM is written to some area on the disk and the computer is completely powered off (including the RAM).

Stefan

Message #5 - Posted 2004/05/05 - clvrmnky

On 05/05/2004 4:42 PM, Stefan Monnier wrote:

Is the PowerBook in true hibernation mode?

Just for the record: I got confusd by your post.
In my world "hibernation" is different from "suspend": it stands for "suspend to disk" (which doesn't exist on my PowerBook, BTW) which means that your RAM is written to some area on the disk and the computer is completely powered off (including the RAM).

No confusion necessary. There is really only one "sleep" for OS X, which is a near-complete power-save suspend mode pretty much identical to your definition of hibernation. It is not completely powered off, as a small amount of power is still routed to specific hardware. On my G4, the power supply still makes a *tiny* amount of heat while in full sleep. Apple claims that a G4 consumes about a days worth of normal operation power in one month when in sleep mode.

Whether or not this aligns with any other hardware manufacturers idea of hibernation is irrelevant. Since neither the term "hibernate" nor "suspend" are used in the Energy Saver panel, it really doesn't matter, does it? The question was whether networking would work while the Mac was in sleep mode. While the answer is "no", this is only if what I think the OP meant by sleep is what I think he means.

I took pains to contrast that with a dark screen, parked hard disk and fully stopped fans that many refer to as "sleep". With a laptop, the difference is not immediately apparent.

Hence my use of the word "hibernation" (which is not an OS X term, anyway, so your definition is not any clearer in this context) to distinguish between the two states.

cm

Message #6 - Posted 2004/05/06 - Pete Verdon

Stefan Monnier wrote:

In my world "hibernation" is different from "suspend": it stands for "suspend to disk" (which doesn't exist on my PowerBook, BTW) which means that your RAM is written to some area on the disk and the computer is completely powered off (including the RAM).

Yes, I think those are the meanings commonly used in the Windows (and to some extent, Linux) worlds. From what I've read, Macs don't do suspend-to-disk. Instead, since Apple makes the hardware they can have it do whatever they want, which in this case is to power only the RAM and a small circuit that supports it. This document:

http://developer.apple.com/documentation/Hardware/Developer_Notes/Macintosh_CPUs-G4/15inchPowerBookG4/4Expansion/chapter_5_section_2.html#//apple_ref/doc/uid/TP40001086-CH208-TPXREF102 under the heading "DDR SDRAM Devices"

refers to a self-refresh mode that any extra RAM must have, and which is used during sleep mode to retain the contents.

Pete

Message #7 - Posted 2004/05/06 - stan

In comp.sys.mac.system Norm wrote:

Trying to understand the "sleep" function in Energy Saver.

Can I connect to a computer that is in Sleep mode?

What do you mean by "connect?" If you mean you want to access the computer
remotely via the computer's ethernet port, then you can, but you need to set the "wake on ethernet network administrator access" option in the engergy saver preference panel. I am assuming you're using Mac OS X.

Can a program launch at a set time when a computer is in Sleep mode?

If Powerbook is powered by Power Adapter not battery is there any benefit to Sleep the computer?

Yes. Keeps the computer cooler. Saves on having the disk drive and monitor
run when they are not needed.

Background: I'm able to access my wife's Powerbook both to do a Retrospect backup and connect from my Mac even though her Mac's screen is dark and the energy settings are set to sleep the system and display at same time after10 minutes. So by that I'm assuming her Powerbook is in Sleep mode when screen dark. But I didn't think it should respond to Retrospect or to attempts to connect from another computer when in Sleep. So I'm confused.

You need to familiarize yourself with the options that are available in the energy preferences panel. There is no great mystery to this.

Message #8 - Posted 2004/05/05 - Norm

Previously, stan@temple.edu wrote:

In comp.sys.mac.system Norm wrote:

Trying to understand the "sleep" function in Energy Saver.

Can I connect to a computer that is in Sleep mode?

What do you mean by "connect?" If you mean you want to access the computer
remotely via the computer's ethernet port, then you can, but you need to set the "wake on ethernet network administrator access" option in the engergy saver preference panel. I am assuming you're using Mac OS X.

Yes, I meant connect over LAN and use file sharing.

Using OS X on one and OS 8.6 on other.

Thanks.

Please send email to: nwhiii at yahoo dot com

Message #9 - Posted 2004/05/06 - Daniel Cohen

clvrmnky wrote:

The question was whether networking would work while the Mac was in sleep mode. While the answer is "no", this is only if what I think the OP meant by sleep is what I think he means.

Agreed. As another poster has mentioned, there are programs (such as Wake550) that will send "Wake-on-LAN" packets to a slepping machine. This does not work on when connecting to machines with Airport cards rather than by ethernet cables, though, as the card has to be active to receive any packet.

The OP also asked whether programs could run when the machine is asleep. Again, the answer is "No", but there are programs such as iBeeZz that allow one to schedule any number of wake and sleep actions.

I took pains to contrast that with a dark screen, parked hard disk and fully stopped fans that many refer to as "sleep". With a laptop, the difference is not immediately apparent.

Some people use the phrase "deep sleep" for the full sleep you referred to earlier. At least, I huess that is what "deep sleep" means, I've never seen it defined.

The screen can be darkened by Display Sleep in the Energy Saver preference pane, and the hard disks can be parked using a check box in that pane. What would stop the fans except for the full sleep you describe?

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Message #10 - Posted 2004/05/06 - John Johnson

Previously, Daniel Cohen wrote:

[snip]

The screen can be darkened by Display Sleep in the Energy Saver preference pane, and the hard disks can be parked using a check box in that pane. What would stop the fans except for the full sleep you describe?

That depends on the machine. On my Pismo, the fan almost never runs (when watching DVD's, it runs sometimes). Even more recent PowerBooks have been known to run without their fans at some times.

Message #11 - Posted 2004/05/06 - clvrmnky

On 06/05/2004 2:27 AM, Daniel Cohen wrote:

clvrmnky wrote:

The question was whether networking would work while the Mac was in sleep mode. While the answer is "no", this is only if what I think the OP meant by sleep is what I think he means.

Agreed. As another poster has mentioned, there are programs (such as Wake550) that will send "Wake-on-LAN" packets to a slepping machine. This does not work on when connecting to machines with Airport cards rather than by ethernet cables, though, as the card has to be active to receive any packet.

I use a "wakeonlan" Perl script to do this. Same difference. You just need a way to send the magic packet to the appropriate MAC address and (in my case) the correct netmask. I've got another little native OS X app that does the same. I never use it because I almost always run wakeonlan from an edge box running OpenBSD.

I took pains to contrast that with a dark screen, parked hard disk and fully stopped fans that many refer to as "sleep". With a laptop, the difference is not immediately apparent.

Some people use the phrase "deep sleep" for the full sleep you referred to earlier. At least, I huess that is what "deep sleep" means, I've never seen it defined.

The screen can be darkened by Display Sleep in the Energy Saver preference pane, and the hard disks can be parked using a check box in that pane. What would stop the fans except for the full sleep you describe?

I was referring to Mac laptops, which seem to spin down the fans when idle. I'm assuming this is because they are temperature controlled.

Since the OP was talking about a laptop, I thought this was significant when determining if the laptop was, in fact, asleep.

Even Apple doesn't seem to distinguish between all these states a Mac might be in, or give them names. So we don't have a common accurate lexicon to refer to a Mac that might, or might not be "asleep" for any given definition of "asleep". I imagine that Apple Support has to go through similar checklist of standard "is your computer doing the following...?" questions when diagnosing sleep problems. --
cm

Message #12 - Posted 2004/05/06 - Stefan Monnier

No confusion necessary. There is really only one "sleep" for OS X, which is a near-complete power-save suspend mode pretty much identical to your definition of hibernation.

No, what you describe is "suspend". The difference is significant. The issue of power consumption is one aspect, but the issue of the state of the hardware is the more important one. In hibernation mode, the computer is 100% off: you can open it, replace memory card, rip out the drive, ... without any risk (it may not properly wake up, admittedly, but you don't risk frying your hardware).
Also since the hardware state is different, it may react differently w.r.t wake-on-lan and things like that.

Finally, contrary to suspend, hibernation can be implemented 100% in software and used on machines not designed for it (such as desktops).

I understand that on Mac OS X hibernation doesn't exist, so the distinction is partly moot, for I was just pointing out that your use of "hibernation" can confuse people whose world is not limited to Macs.

Stefan

Message #13 - Posted 2004/05/06 - clvrmnky

On 06/05/2004 11:35 AM, Stefan Monnier wrote:

No confusion necessary. There is really only one "sleep" for OS X, which is a near-complete power-save suspend mode pretty much identical to your definition of hibernation.

No, what you describe is "suspend". The difference is significant. The issue of power consumption is one aspect, but the issue of the state of the hardware is the more important one. In hibernation mode, the computer is 100% off: you can open it, replace memory card, rip out the drive, ... without any risk (it may not properly wake up, admittedly, but you don't risk frying your hardware).
Also since the hardware state is different, it may react differently w.r.t wake-on-lan and things like that.

[...]

It seems to me that your working definition for the various powersave modes we are discussing is skewed toward win32.

My comments were accurate within context. I don't care what other manufacturers refer to as "hibernate" or "sleep" or whatever. Even if these are defined by some governing body, this has no bearing on the discussion with respect to the original query.

This just does not matter to the OP, and it does not matter to Apple users. My intention was to be very clear about what state the laptop is in when talking about laptop that was sleeping. I was simply making it clear what I meant by "deep sleep" so I could, you know, help out a bit.

I understand that on Mac OS X hibernation doesn't exist, so the distinction is partly moot, for I was just pointing out that your use of "hibernation" can confuse people whose world is not limited to Macs.

Exactly my point. Sheesh.

cm

Message #14 - Posted 2004/05/25 - Peter Renzland

Previously, clvrmnky wrote:

On 05/05/2004 4:42 PM, Stefan Monnier wrote:

No confusion necessary. There is really only one "sleep" for OS X, which is a near-complete power-save suspend mode pretty much identical to your definition of hibernation. It is not completely powered off, as a small amount of power is still routed to specific hardware. On my G4, the power supply still makes a *tiny* amount of heat while in full sleep. Apple claims that a G4 consumes about a days worth of normal operation power in one month when in sleep mode.

That's exactly the battery consumption ratio I measure on my 500 Mhz G3 iBook: 400 mA doing nothing, 14 mA sleeping.

BTW, when on battery, there is a second "coma" sleep mode which requires power connection (or, on a hot-swap laptop)
a non-depleted battery(?)) to wake up from.

-- Peter

Message #15 - Posted 2004/05/26 - John Johnson

Previously, Peter Renzland wrote:

Previously, clvrmnky wrote:

On 05/05/2004 4:42 PM, Stefan Monnier wrote:

No confusion necessary. There is really only one "sleep" for OS X, which is a near-complete power-save suspend mode pretty much identical to your definition of hibernation. It is not completely powered off, as a small amount of power is still routed to specific hardware. On my G4, the power supply still makes a *tiny* amount of heat while in full sleep. Apple claims that a G4 consumes about a days worth of normal operation power in one month when in sleep mode.

That's exactly the battery consumption ratio I measure on my 500 Mhz G3 iBook: 400 mA doing nothing, 14 mA sleeping.

BTW, when on battery, there is a second "coma" sleep mode which requires power connection (or, on a hot-swap laptop)
a non-depleted battery(?)) to wake up from.

Is this actually a different mode, or is it the same sleep mode, interacting with a "stronger rule" for waking up? I mean, is there something different about what's powered in the "coma" sleep, or is it the regular sleep mode, with the additional constraint that it won't wake up without adequate power (which constraint could be active at all times, but you only notice it when the battery is dead, etc.)?

-- Peter

Later,
John

johajohn@indianahoosiers.edu

'indiana' is a noun. Leave only the noun between @ and .edu to reply

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