31:
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55:) is a low power mode for electronic devices such as computers, televisions, and remote controlled devices. These modes save significantly on electrical consumption compared to leaving a device fully on and, upon resume, allow the user to avoid having to reissue instructions or to wait for a machine to
102:
and, when placed in sleep mode, the computer cuts power to unneeded subsystems and places the RAM into a minimum power state, just sufficient to retain its data. Because of the large power saving, most laptops automatically enter this mode when the computer is running on batteries and the lid is
295:
began to support Safe Sleep. The feature saves the contents of volatile memory to the system hard disk each time the Mac enters Sleep mode. The Mac can instantaneously wake from sleep mode if power to the RAM has not been lost. However, if the power supply was interrupted, such as when removing
160:
Sleep mode and hibernation can be combined: the contents of RAM are first copied to non-volatile storage like for regular hibernation, but then, instead of powering down, the computer enters sleep mode. This approach combines the benefits of sleep mode and hibernation: The machine can resume
151:
on Linux, saves all computer operational data on the fixed disk before turning the computer off completely. On switching the computer back on, the computer is restored to its state prior to hibernation, with all programs and files open, and unsaved data intact. In contrast with standby mode,
211:. When a non-ACPI device is plugged in, Windows will sometimes disable stand-by functionality for the whole operating system. Without ACPI functionality, as seen on older hardware, sleep mode is usually restricted to turning off the monitor and spinning down the hard drive.
230:'s Hybrid sleep feature saves the contents of volatile memory to hard disk before entering sleep mode. If power to memory is lost, it will use the hard disk to wake up. The user has the option of hibernating directly if they wish. On PCs that enable
314:(10.8) and select Mac models. Power Nap allows the Mac to perform tasks silently, such as iCloud syncing and Spotlight indexing. Only low energy tasks are performed when on battery power, while higher energy tasks are performed with AC power.
152:
hibernation mode saves the computer's state on the hard disk, which requires no power to maintain, whereas standby mode saves the computer's state in RAM, which requires a small amount of power to maintain.
77:
In computers, entering a sleep state is roughly equivalent to "pausing" the state of the machine. When restored, the operation continues from the same point, having the same applications and files open.
161:
instantaneously, but it can also be powered down completely (e.g. due to loss of power) without loss of data, because it is already effectively in a state of hibernation. This mode is called "
413:
Equivalent terms include wake on WAN, remote wake-up, power on by LAN, power up by LAN, resume by LAN, resume on LAN and wake up on LAN. If the computer being awakened is communicating via
252:
integration and per-user/per-machine settings with the more advanced offering multiple power plans, scheduled power plans, anti-insomnia features and enterprise power usage reporting.
498:
402:, which was co-developed by AMD and Hewlett-Packard, following its proposal as a standard in 1995 – The standard saw quick adoption thereafter through
573:
642:
800:
110:
A computer must consume some energy while sleeping in order to power the RAM and to be able to respond to a wake-up event. A sleeping PC is on
534:
222:
and later support sleep at the operating system level (ACPI S3 state) without special drivers from the hardware manufacturer, except of
118:, from 2010. In addition to a wake-up press of the power button, PCs can also respond to other wake cues, such as from keyboard, mouse,
192:
72:
430:
The WoL and WoWLAN standards are often supplemented by vendors to provide protocol-transparent on-demand services, for example in the
348:. In February 2015, the proposal was accepted by Unicode and the characters were included in Unicode 9.0. The characters are in the "
296:
batteries without an AC power connection, the Mac would wake from Safe Sleep instead, restoring memory contents from the hard drive.
661:
248:
software exists for newer versions of
Windows, offering features beyond those built into the operating system. Most products offer
559:
241:
without resorting to third-party software. As a result, these earlier versions of
Windows were criticized for wasting energy.
592:
17:
846:
336:
114:, and this is covered by regulations in many countries, for example in the United States limiting such power under the
394:
standard that allows a computer to be turned on or awakened from sleep mode by a network message. It is based upon
851:
841:
420:
The message is usually sent to the target computer by a program executed on a device connected to the same
646:
624:
516:
376:
A physical Wake-on-LAN connector (white object in foreground) featured on the IBM PCI Token-Ring
Adapter 2
280:, Safe Sleep is referred to as sleep. Since Safe Sleep also allowed state to be restored in an event of a
238:
774:
237:
In older versions prior to
Windows Vista, sleep mode was under-used in business environments as it was
739:
502:
344:
Because of widespread use of this symbol, a campaign was launched to add a set of power characters to
810:
473:
200:
349:
332:
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142:
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130:
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Safe Sleep capability is found in Mac models starting with the
October 2005 revision of the
448:
99:
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245:
115:
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421:
311:
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166:
590:
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249:
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104:
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417:, a supplementary standard called Wake on Wireless LAN (WoWLAN) must be employed.
173:
453:
304:
292:
231:
835:
227:
223:
177:
111:
42:
424:. It is also possible to initiate the message from another network by using
685:
662:"What is Power Nap? Power Nap Macs & Hack Possibilities @ EveryMac.com"
300:
281:
119:
34:
30:
380:
365:
195:(Advanced Configuration and Power Interface) is the current standard for
123:
372:
388:
610:
261:
203:(Advanced Power Management) and providing the backbone for sleep and
59:. Many devices signify this power mode with a pulsed or red colored
805:
384:
345:
56:
355:
The symbol is ⏾ (⏾)—defined as "Power Sleep Symbol".
414:
407:
265:
181:
643:"How to Safe Sleep (Hibernate) Your Mac - AndrewEscobar.com"
593:"HMC: A Practical Guide to Sustainable Building for Schools"
757:"Unicode Chart - Miscellaneous Technical - Range: 2300–23F"
574:"Activating Power Management: Commercial Software Packages"
801:"Wake on Demand lets Snow Leopard sleep with one eye open"
792:
403:
395:
207:
on modern computers. Sleep mode corresponds to ACPI mode
103:
closed. If undesired, the behavior can be altered in the
60:
535:"EcoGeek - How Windows XP Wasted $ 25 Billion of Energy"
517:"PowerMAN PC Power Management Software Documentation"
560:"Power Management Software for Windows Workstations"
133:can schedule the computer to wake from sleep mode.
41:"Safe sleep" redirects here. For the campaign, see
751:
749:
591:The Headmasters' and Headmistresses' Conference.
833:
86:Sleep mode has gone by various names, including
425:
746:
172:A hybrid mode is supported by some portable
184:distributions running kernel 3.6 or newer.
823:How it works, Energy Saver preference pane
73:Advanced Configuration and Power Interface
798:
310:In 2012, Apple introduced Power Nap with
772:
371:
29:
337:question marks, boxes, or other symbols
234:, Hybrid sleep feature is unavailable.
176:computers, compatible hardware running
14:
834:
710:"Unicode Proposal 14009 Power Symbol"
239:difficult to enable organization-wide
27:Low power mode for electronic devices
773:von Nagy, Andrew (8 November 2010).
737:
214:
799:Fleishman, Glenn (28 August 2009).
352:" block, with code points 23FB-FE.
268:consists of the traditional sleep,
24:
284:, unlike other operating systems,
120:incoming telephone call on a modem
25:
863:
686:"How Power Nap works on your Mac"
645:. January 5, 2008. Archived from
611:"OS X Lion: What is safe sleep?"
364:This section is an excerpt from
288:was never offered as an option.
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136:
13:
1:
459:
740:"What's new in Unicode 9.0?"
625:"What is safe sleep on Mac?"
307:or higher is also required.
66:
7:
847:Operating system technology
738:West, Andrew (2016-01-10).
501:. Apple Inc. Archived from
442:
428:or a WoL gateway service.
291:In 2005, some Macs running
98:. Machine state is held in
10:
868:
426:subnet directed broadcasts
363:
317:
140:
107:settings of the computer.
70:
40:
244:A variety of third-party
147:Hibernation, also called
124:local area network signal
37:standardized in IEEE 1621
255:
81:
400:Magic Packet Technology
350:Miscellaneous Technical
187:
169:other than Windows XP.
143:Hibernation (computing)
852:Windows administration
775:"Wake on Wireless LAN"
377:
325:This article contains
220:Microsoft Windows 2000
38:
779:Revolution Wi-Fi Blog
521:www.datasynergy.co.uk
375:
131:real-time clock alarm
33:
18:Standby (electricity)
813:on 16 September 2009
719:. Unicode Consortium
449:Shutdown (computing)
842:Energy conservation
392:computer networking
383:(WoL or WOL) is an
303:(Double-Layer SD).
246:PC power management
116:One Watt Initiative
578:www.energystar.gov
499:"About safe sleep"
422:local area network
378:
327:special characters
312:OS X Mountain Lion
278:System Preferences
39:
660:LLC, Kyle Media.
505:on April 2, 2012.
333:rendering support
215:Microsoft Windows
167:Microsoft Windows
35:Sleep mode symbol
16:(Redirected from
859:
826:
825:
820:
818:
809:. Archived from
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666:www.everymac.com
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595:. Archived from
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537:. Archived from
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434:wake-on-demand (
250:Active Directory
197:power management
105:operating system
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478:freedesktop.org
474:"systemd.timer"
472:
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369:
361:
342:
341:
340:
331:Without proper
320:
258:
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174:Apple Macintosh
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149:Suspend to Disk
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139:
84:
75:
69:
46:
28:
23:
22:
15:
12:
11:
5:
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855:
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791:
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649:on 2008-01-05.
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599:on 2012-03-15.
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454:Modern Standby
451:
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335:, you may see
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322:
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305:Mac OS X v10.4
293:Mac OS X v10.4
257:
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232:Modern Standby
224:video adapters
216:
213:
199:, superseding
189:
186:
180:or newer, and
157:
154:
141:Main article:
138:
135:
96:Suspend to RAM
83:
80:
71:Main article:
68:
65:
53:suspend to RAM
26:
9:
6:
4:
3:
2:
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762:. 2016-06-22.
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691:
690:Apple Support
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629:Apple Support
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541:on 2006-11-27
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432:Apple Bonjour
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228:Windows Vista
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178:Windows Vista
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112:standby power
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64:
63:power light.
62:
58:
54:
50:
44:
43:Safe to Sleep
36:
32:
19:
822:
817:15 September
815:. Retrieved
811:the original
804:
794:
782:. Retrieved
778:
768:
733:
721:. Retrieved
716:
704:
693:. Retrieved
689:
680:
669:. Retrieved
665:
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647:the original
637:
628:
619:
605:
597:the original
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577:
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543:. Retrieved
539:the original
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503:the original
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481:. Retrieved
477:
468:
419:
412:
410:and others.
399:
379:
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301:PowerBook G4
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282:power outage
273:
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163:hybrid sleep
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156:Hybrid sleep
148:
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52:
48:
47:
436:Sleep Proxy
381:Wake-on-LAN
366:Wake-on-LAN
359:Wake-on-LAN
205:hibernation
137:Hibernation
836:Categories
784:28 October
695:2017-02-02
671:2017-02-02
545:2011-04-19
483:27 October
460:References
438:) feature.
389:Token Ring
270:Safe Sleep
49:Sleep mode
286:hibernate
274:Power Nap
260:Sleep on
67:Computers
806:Macworld
443:See also
385:Ethernet
264:running
88:Stand By
723:Dec 23,
717:Unicode
346:Unicode
318:Unicode
92:Suspend
272:, and
760:(PDF)
713:(PDF)
415:Wi-Fi
408:Intel
276:. In
266:macOS
256:macOS
182:Linux
165:" in
122:, or
82:Sleep
819:2009
786:2015
725:2015
485:2014
262:Macs
193:ACPI
188:ACPI
94:and
57:boot
51:(or
404:IBM
398:'s
396:AMD
387:or
201:APM
100:RAM
61:LED
838::
821:.
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777:.
748:^
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209:S3
129:A
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727:.
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562:.
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523:.
487:.
368:.
339:.
329:.
45:.
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.