© Magnani Rocca Foundation, via Reuters
© Shiho Fukada for The New York Times
There are two ways to restart a Mac that’s already running: you can either use the Apple menu command Restart (or an equivalent in Terminal), or you can shut it down, leave it a few seconds, and start it up afresh in what’s known as a cold boot. This article examines whether there’s any difference, and which you should prefer.
When a desktop Mac starts up from cold, its power supply starts providing power to its internal components, and when the boot process starts they are all initialised from their power-off state. There’s one small exception to that in the internal clock, possibly part of the Always On Processor (AOP) in Apple silicon Macs.
It’s commonly held that a regular (or warm) restart doesn’t interrupt the power supplied to internal components, as Intel Macs may not undergo power-on self-testing (POST) when only restarted. That doesn’t appear to be correct, though, as it’s easily demonstrated that Intel Macs with T2 chips do undertake a POST during a restart. Apple silicon Macs don’t appear to perform a similar form of POST. Neither does there appear to be any difference for peripherals, which are shut down before being started up again whether the Mac is booted warm or cold.
It’s also most unusual to attempt a true cold boot, particularly in a laptop. To remove all power from a desktop Mac requires it to be disconnected from its mains power supply, and for a laptop the internal battery also needs to be isolated or removed, something only performed during service by a technician.
What is clear is that the period during which power is turned off is very different: during a warm restart that’s only a second or two.
Received wisdom is that this allows data to be retained in memory through a warm restart, but that it’s wiped clean after a cold boot. This was first documented by Alex Halderman and others, who used it to perform ‘cold boot’ attacks to recover encryption keys. They demonstrated that RAM contents were still recoverable many seconds after shutting down, and could be used to recover encryption keys and other critically secure data. A great deal has changed since that research was undertaken. As far as the protection of secrets is concerned, all modern Macs have secure enclaves and use Extended Anti-Replay Technology (xART) to prevent that.
It’s thus plausible that there could be some differences in hardware between a restart and a cold boot, but careful comparison of log entries during booting from a Mac’s internal SSD fails to reveal any significant differences there.
There appears to be no useful evidence for recent and current Macs to determine how long you should wait between shutdown and a cold boot. Periods given range widely, from a few seconds to a minute or more.
There are many reports of cold boots resolving problems that weren’t affected by a warm restart, but those are generally if not exclusively for Intel Macs, and most usually those without T2 chips.
I have only once experienced a problem in an Apple silicon Mac that required a cold boot, and that occurred a couple of years ago with a dual-boot setup that wouldn’t restart into its primary macOS on its internal SSD, but would do so when started up with a cold boot.
Cold booting is sometimes recommended following more severe problems, such as a freeze or kernel panic. As the normal way to recover from a frozen Mac is to force shutdown using the Power button, there is no option other than a cold boot. Kernel panics should normally result in an automatic restart, the behaviour that demonstrates that a panic took place, and only after that restart is the panic confirmed in an alert, from where the panic log can be accessed. There is no option to perform a cold boot until after the restart. Apple silicon Macs are almost invariably cold booted into Recovery or Safe mode, as those require a long hold of the Power button.
Thus the choice between a restart and a cold boot is usually determined by the problem that has occurred.
阅读这篇文章的人有两种：
第一种，是原本就关注了这个博客的读者，或者通过视频、图文等各种社交媒体找过来的观众，你们应该是这个项目相关视频的观众，或者通过这篇博客知道了这个项目的读者，总之，东西不在你们手里；
第二种，是找到了指定地点，并找到了这件作品，同时发现了它背后的二维码，扫码进入了这个页面的幸运儿。
如果你是第二种人，恭喜你！这件作品，现在送给你了：）
如果你愿意把你在现场与这件作品的合照（无需露脸），以及这件作品的多角度照片（不少于 3 张），发布在微博和小红书上（两个平台一起发布哦），并带上 #苏志斌3Dfiti# 这个标签，我将为你定制一件 3D 打印作品。当你分享完之后，请把这两个平台的链接发送至以下这个邮箱：
suithink.su@gmail.com
我们将在后续的沟通里，一起完成为你定制的作品。
这是一系列艺术创作项目的开始，是第一件作品。
这件作品中的造像，是来自四川毗卢洞紫竹堂的水月观音，它是宋代的杰作，是举世公认的艺术文化瑰宝。因作品场地空间特殊，故将造像左右翻转，与原造型呈镜像关系。
我参与 3DFiti 这个艺术项目，旨在通过 3D 扫描和 3D 打印技术，使我们生活的周边环境增加一些趣味性和艺术性。在人类学家项飙（英国牛津大学社会人类学教授，德国马克斯普朗克社会人类学研究所所长）所描述的那个「附近」的概念之中延展出来，一切我可以到达的地方，只要有我感兴趣的公共区域内的「缺损」部分，就有可能成为这个艺术项目的创作对象。
我通过 iPhone 扫描空间或者物体，并对模型进行二次创作，使用 3D 打印技术将其制作成一件真实的物品，即能够与现场的「缺损」相嵌合的物件，使这个「缺损」转化为一处临时的微型艺术场所。
No.001 作品中的 紫竹观音像 3D 模型，是来自 Funes.world 的文件。他们的工作是在人类从原子社会进入到比特社会的过程中，将原本属于原子世界中的建筑、空间、故事，通过 3D 扫描建模的方式，将其保存在数字世界中，建成一座人类文明的数字空间博物馆。
如果你想观看 No.001 作品的相关视频，可以点击链接：
https://www.bilibili.com/video/BV1ShGvzwEeB/
或点击下方图片：
“这座微型雕塑？跟随影片线索去发现吧！藏在城市褶皱中的精美作品，属于第一个破解谜题的人！”
期待你也参与到这个项目之中
拓展阅读：
水月观音是汉传佛教中国化的典范，以“水中月”喻诸法皆空，融合《华严经》哲思与文人山水意境。其形象由中唐周昉首创，经宋元演化定型：唐五代为半裸髭须的男性，宋代后转为慈美女性，体态婀娜如安岳毗卢洞紫竹观音，背倚紫竹，跷足坐于莲台，衣纹流畅如“S”曲线，被誉为“东方维纳斯”。
坐姿核心为“自在”：
赤足触水喻“普渡”，手持杨柳、净瓶显慈悲，姿态从庄重禅定转向世俗洒脱，折射佛教本土化进程。其造像以圆月、竹石为境，突破宗教程式，成就敦煌壁画、大足石刻等艺术巅峰，更渗入民间故事（如榆林窟唐僧取经图），成为宗教与世俗美学的融合象征。
精髓：以空性为核，化仪轨为诗意——紫竹观音跷足斜倚之姿，既承“观自在”禅悟，亦凝唐宋工匠“以形写神”的至高境界，堪称佛教艺术中国化的里程碑。
其实有点出乎我意料，除了 Apple Vision Pro 那期，最受欢迎的居然是聊《九龙城寨》和《暗恋桃花源》的这两期。而且，刚发的《谈判专家》这期的收听量也在稳定上涨。聊 AI 那期尽管内容很多，但收听量比这些都少得多。
从博客后台数据能看到，最近一周的主要收听量中，三分之二都来自这三期聊戏聊剧的节目。
我原本以为，收听我节目的主要人群，是过去在知乎和 B站看我讲设计的读者和观众。
这么看下来，我有一个猜测：收听我播客的人群当中，有很大一部分比例，可能是此前并不认识我的路人，他们对科技类话题的兴趣，没有对娱乐类型的话题高。
挺好的，这也挺符合我最初对播客的预期，这样我就可以不用老聊设计和产品了！
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Spotify：荒野楼阁 WildloG
YouTube：荒野楼阁 WildloG
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