Difference between Screen-Saver and Sleep?

Discussion in 'Mac Basics and Help' started by doubledee, Jul 23, 2013.

  1. doubledee macrumors 6502


    May 14, 2012
    This may sound like a dumb question, but I'm not entirely sure that I understand the difference between when my Screen-Saver comes on and when my computer falls into Sleep mode... :confused:

    I am asking this question as part of a larger issue, which is that on my new cMBP, there seems to be a problem with my Screen-Saver, Sleep, and losing my Wi-Fi Connections.

    So before I tackle that issue, I figured I better make sure I understand what different terms mean and how Mountain Lion is actually working.

    Here is hoping you guys can (once again) help edumacates me!! :D


  2. Intell macrumors P6


    Jan 24, 2010
    A screen saver is when the CPU is still active and processing stuff, mostly what is being shown on the screen. Sleep is when the CPU isn't powered on and not doing anything with only the memory using power, the screen is completely off when sleeping.
  3. samh macrumors 6502

    Oct 29, 2009
    Sleep refers to a (lower) power state. A screen saver is essentially a full screen app that prevents screen burn-in on certain kinds of displays by showing an image that changes over time... Like a photo slide show or random geometric shapes.

    Your Mac has two different capabilities related to sleep. One is that after a certain period of time your Mac can put the display to sleep. The computer is still on as normal but the power to the display is sharply reduced so that it is for all intents and purposes off. If you have an cerebral monitor the power light will usually glow something like orange rather than default green to indicate that it's circuitry is still powered on but the display itself is off.

    The Mac system itself can also go into a low power sleep mode. Apps do not continue running normally. Everything is essentially frozen.

    By default I believe your Mac is set to have the same timer for putting the display to sleep and for the screensaver to kick in. Most users do not see their screen save under default settings.
  4. doubledee thread starter macrumors 6502


    May 14, 2012
    Let me repeat what has been said so far...

    So the screen-saver just puts the monitor to "sleep" (or "pseudo-sleep" if you have stuff dancing around the screen).

    And when my MacBook goes to "sleep", it is the CPU that is slowing down/stopping. So anything I am working on would still exist in Memory (e.g. an unsaved document), but it's basically like everything was placed on "pause", right?

    So, now on to my larger problem...

    On my new cMBP, I want things set up in Mountain Lion to do this...

    - My Screen-Saver should kick in after 5 minutes.

    - Since I have "Require password immediately after sleep or screen-saver begins" checked under the Security section, that should lock my computer to others

    - I guess I am indifferent to putting my CPU to "sleep" except maybe when I am running on the Battery

    - Most importantly, when my Screen-Saver kicks in, I do NOT want to lose my Internet Connection!! (That is not happening on this old MacBook with Snow Leopard, but it *is* happening with my new cMBP and Mountain Lion...) :mad:

    - I'm not sure what to expect if my CPU went to "sleep".

    According to my settings on my MacBook, "Computer Sleep" set to 10 minutes, but when I am recording a streaming radio show using Audacity, I cannot ever remember my old MacBook every dropping the Internet Connection...

    THAT is the behavior I'd expect. That is, whether I am actively using my laptop, or I step away for an hour, I want my Screen-Saver on protecting my laptop, HOWEVER, I still want the Internet up and running and my Streaming Radio Show AND Audacity running the whole time.

    What is going wrong with Mountain Lion to prevent this?? :confused:


  5. DianeK macrumors regular

    Jun 4, 2013
    This one of the known problems with ML. Just do a search and you will find a plethora of complaints. ML is to SL what Vista was to XP.
  6. dusk007 macrumors 68040


    Dec 5, 2009
    Usually the app needs to tell the OS that it is still doing something worthwhile to keep it from considering it idle just because there are no keyboard/mouse inputs.
    I assume that doesn't work anymore with ML. It is just a misccommunication between application and OS. The OS thinks nothing is happening and the app would have to tell it that this is not the case.
    Personally I never really bother.

    Just go into the energy settings and set the computer to sleep on "never". Change it back when you need to. You can have different settings for battery power and on the wall. If you set it to never, you just have to turn it off (into sleep) yourself by closing the lid.
    Set the display to sleep whenever you don't need it anymore. A sleeping display is just off; the notebook keeps running just fine.

    Forget about screen savers. They are a thing of the past for different screen technologies (CRTs). Today they are just a fancy animation that is a huge waste of power and creates a lot of heat for nothing. Don't ever use a screen saver. They aren't used in default settings for a reason. Put the display to sleep (ctrl+shift+eject for the immediate) if you don't need it or leave it on if you do need it.

    If a computer is in sleep mode (also known as Stand by), it is for all intents and purposes OFF. It is not doing anything. The only difference to being shutdown is that it starts up more quickly. The main memory stays powered so it can resume.
  7. doubledee thread starter macrumors 6502


    May 14, 2012
    Here is what I have discovered so far from reading online and doing LOTS of testing last night between this old MacBook and my new cMBP...

    First of all, there are 3 types of "sleep"...


    Secondly, I quit all apps last night on both my Macs, and while the Display Sleep mode kicked in, I couldn't get the HDD to spin down in a reasonable period of waiting, so by the description above, I wasn't about to attain System Sleep while my cover was open.

    Thirdly, in retrospect, I am not sure the exact activities - or lack thereof! - that occurred on Sunday which made my new cMBP drop the Internet Connection.

    I do know that I would not have had any application open keeping OS-X busy, so the HDD may have eventually spun down and thus things went into System Sleep, thus dropping the Internet connection.

    Fourthly, one reason I may never have had an issue with my old MacBook, is that if I have FireFox open with a streaming radio show on, AND I have Audacity recording, the HDD would *never* spin down, and so while my System Preferences were technically set to enter into System Sleep over a period of Keyboard/Trackpad inactivity, those two apps would keep the screen-saver on, while HDD zoomed away.

    Finally, I also noticed that if I do a...
    Control + Shift + Eject
    ...things immediately go into Display Sleep and my screen-saver kicks in, but the apps in the background are fine.

    By contrast, if I do a...
    Command + Option + Eject
    ...things go immediately into System Sleep and my screen-saver kicks in, AND the Internet gets dropped.

    So that set of keystrokes or closing the lid really does a TRUE SLEEP, whereas inactivity - in my personal case - doesn't seem to be enough to ever reach the "true sleep" state of SYSTEM SLEEP?!

    Weird, right?! :cool:

    Anyways, I think I figured out what was going on with my new cMBP, and I know what I need to do/not do to get the desired end result of not interrupting my radio shows while I am away from my laptop!! :)


  8. samh macrumors 6502

    Oct 29, 2009
    That may be true in Debbie's case and for some people, but it's not a universal. For one thing, plasma displays can suffer from burned-in images. Secondly, there are instances when a computer is driving a display and it's better for it to be on and showing some "useless animation" than sleeping. For example, a computer functioning as a home theater center that is only playing music might be better off in some cases showing an album-art related screen save or photo slideshow (see Apple TV for one).

    So they may not need to be on by default but you certainly can't say they have been completed obviated either.

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