Laptop Sleep Problem

[Grieverheart]

Hi, I have configured my laptop so that it goes to sleep when closing the lid (inspired by Mac). I have encountered a problem though...after leaving the laptop in sleep mode but plugged off, it turns completely off after some time. After turning it on again, the battery seems fine. I have not yet checked how much time it takes for it to turn completely off. Also, I don't think this could be some OS setting that causes it, right?

 

[cluberti]

It is - if you go into the Power options, and edit your current power plan, in the "Sleep" section there is an item for "hibernate after:" and a timer. The machine is likely hibernating after that timeout has expired after putting the machine to sleep, and this is normal. You can disable this if you expect to resume from sleep before your battery would expire whilst sleeping (which I will admit, on a good battery, should be a very long time).

 

[linnemeyerhere]

Grieverheart,
Welcome to SF. I have had too many friends cook their lappy by using this sleep feature. I would suggest against it to spare the laptops mobo and drive. This very feature has cooked two laptops a HP and a Toshiba. It seems convenient right up to the point you realize the problems it's caused are irreversible. I hope this doesn't happen to you !

 

[Grieverheart]

You may be right, I had hibernate activated after 6 hours on battery only. But how does this work? I though that when the computer goes to sleep, only ram is stored and I guessed no such functions would be activated.

 

[cluberti]

If you're hibernating, that would mean you have hybrid sleep enabled too, likely. Making that assumption, here's how it works in a nutshell. When you put the machine to sleep, it's doing both sleep and hibernate operations - the information in RAM is written to disk, and the machine goes into a low-power state (very low power). However, certain system timers still fire (scheduled tasks, power events, etc), and thus when the hibernation timeout passes, the machine simply hibernates (turns off). Since the memory is already on disk, it can just shut off at that point without having to go through most of the laborious process of writing memory to disk.

 

[Grieverheart]

linnemeyerhere I have an Asus laptop and have rarely shut it down in 1.5-2y now and have had no problems at all.

@ cluberti:

So, is the instruction written in the memory and thus is the system reading the memory frequently? To my knowledge, interrupts are written to memory and when read are executed, but my knowledge doesn't go any deeper, so maybe I'm missing something.

 

[linnemeyerhere]

Excellent, and I only hope yours continues to work that way. Both friends routinely placed theirs into sleep modes and when one broke down the service center said it was a common problem with laptops not waking from sleep mode. I on the other hand don't use mine in that manner you're describing and keep all my computers out of sleep mode. But that's just me, like I mentioned I hope your lappy gives you a long normal life.

 

[cluberti]

So, is the instruction written in the memory and thus is the system reading the memory frequently? To my knowledge, interrupts are written to memory and when read are executed, but my knowledge doesn't go any deeper, so maybe I'm missing something.

Program data in memory and CPU state are written to memory when a computer sleeps when hybrid sleep is enabled. I'm not sure what you mean by reading memory frequently though - I think perhaps you're joining your knowledge on multiple subjects.

As to interrupts, those are not written anywhere - they're caused by device drivers or the CPU/BIOS, and as such those would happen when they're encountered. They're not specifically saved anywhere unless they're part of the CPU state (and technically, a pending interrupt would be serviced before the machine went to sleep in most cases).